I remember attending a Chevy/GM event at the Indy 500....all the new cars were on display including engineering cutaways. At the automatic transmission display, I made a comment that my BMW had a GM transmission..if I recall my E46 3 Series Touring used a version of GMs 5L50E..a GM employee at the display said..."well that is one thing we do well." The one clinker we had was on our 1979 Cutlass with the 260 V8....we had the THM-200 which dropped reverse at 78,000 miles. That was a month to remember....the transmission went out in the Cutlass...then my Dad had a heart issue and was hospitalized at the age of 49. So I remember visiting dad at the hospital and talking with the transmission shop and arranging for the transmission to be rebuilt. Some months later, we did get a class action lawsuit notice about a settlement involving the THM-200...but we apparently exceeded the mileage cap. Some years later, on an episode of the Simpsons, Homer pulls into a gas station and asks the attendant if he is hearing a funny noise...the attendant responds, "I think you're having a heart attack." Homer response, "Phew, for a moment there, I thought it was my transmission." I thought of Dad as he had both in the same month. He recovered....and to celebrate, he ended up buying a new boat the following month.....and towed it home using the Cutlass.....
Had a Friend who had a Cutlass with the 260 V8 and the TH200. The transmission went out. So he took it to a local Austin, TX Transmission Shop. The Shop Owner told him that yes, they could rebuild the transmission. But why rebuild a p.o.s. For the same cost they put a TH350 and geared it for the speedometer. It was like night and day when he got the car back.
I bought my wife a used 78 Cutlass with about 25K miles it was loaded sunroof and all. Both the Chevy 305 eng and the TH200 failed. I got a check from GM and bought a Targetmaster 350 and a rebuilt TH350 and we kept that car for almost 20 years
I am a service manager for a national used car retailer, and the 14 up 8 spd transmissions are crud. The "Magic Fluid" flush can stave off internal repairs for a time...but the 1-2 upshift and 2-1 downshift clunks come back and destroys internals. Nice vid!
I work at a GM shop and I HATE the 8spd. I can always immediately tell when a truck has it because of that 1-2 shift and of course the plague torque converter shudder problems.
Who will touch it? LOL I will---any of those (except the stamped planetary carrier THM 200) is simpler and better than the newer electronic POS transmissions. Just rebuilt 2 old Fordomatics, both in 1957 Thunderbirds. Next one up is a Ford AOD upgraded with 4R70w wide ratio planetary set, and then a C6 with extra clutches AND an E4OD wide ratio planetary set. We used to chuck the THM 200s into the scrap pile and replace them with THM 350s
The THM200? Garbage. My mom had one in a new ‘78 Malibu Classic with the 305, and it had problems from the word go. It was in and out of two dealer’s shops even before it was a year old. One dealer suggested annual fluid changes (!). After a few years of dealers dinking with it (and the class action lawsuit which got her something like $50), the case support (the planetary carrier?) broke, then it wouldn’t shift from second to third unless you backed completely off the throttle. A conversion to a rebuilt Turbo 350 by a local indy transmission shop (they were covered up with THM200 problems, and performing 350 conversions) finally fixed it.
TH 350`s had a modulator, the TV cable was for kickdown/passing gear purposes only. The TH 400 had a modulator as you mentioned but it utilized an electrical kickdown/passing gear, they both performed the same function. The TH 200 was a very good transmission if GM had left it in the Chevette like it was designed for, it was ok even for lightweight V6 applications but they chose to put it in everything across the board which was a very bad decision. Most people aren`t as picky about a silky smooth shift as you are (no offense). Stiffer springs could be added to the servo`s and accumulator`s to soften some of that up if a person wanted to modify things. I never liked any lockup convertor, they only have one tiny clutch disc inside of them. I got old, my memory is starting to fade bad. You`re very knowledgeable and speak pleasantly and your videos are very entertaining. I`m new and have been on a binge watching your content. Thank you for all your efforts. :)
I always had great luck with TH 350's; the older ones would handle more torque than what they typically got credit for. The governors are also pretty simple to modify in order to change the shift points to coincide with more torque once the engine had been modified. TCI shift kit to firm up the shifts, grind most of the weight off the governor spring pads and then start messing with different colored springs... with a little experimenting you could usually get the shift points pretty close to where you wanted them. Great transmission. I'm looking forward to see what Adam has to say when he does GM's best list.
I've got a TH200 in my 82 Camaro. I read about the issues they were having with the larger cars so right after I paid off the car. (4yrs.) I noticed a "slip" and carried it to AAMCO to get it checked. They said a bushing went bad and gave me prices and warranty options. At the top end was $200/lifetime guarantee. Knowing what I had , I went for the lifetime warranty. That transmission has been rebuilt 4 separate times. I asked why we were having so many issues and the mechanic admitted that it was designed for the 4cyl engine and couldn't take the torque of a V8. After the second rebuild asked why we couldn't upgrade to a better transmission. GM stopped installing it in the F bodies but the mechanic refused saying that was the transmission that was warranted and that was the transmission that was going to be rebuilt. So every 4 years or 80K miles they would rebuild it. That was the best $200 I ever spent.
Another great video Adam. Some of these have been mentioned below, but don't forget the '58-'59 Buick Triple Turbine Flight Pitch Dynaflow (MUCH less reliable than the standard twin-turbine Dynaflow that was available at the same time). The '57-'61 Chevy Turboglide was based on the same principles (variable pitch stators instead of shifts). Many of the Turboglides got replaced with Powerglides. The Buick Dual Path Dynaflow used only in the '61-'63 Special/Skylark was strange in that it had planetary gears inside of the torque converter. Not sure about reliability on those, but it is a strange design.
Actually, the turbo 350 does have a vacuum modulator valve, as well as a passing gear cable. The difference between a passing gear cable and a throttle valve cable is the transmission with a disconnected passing gear cable will still have a normal life span and shift gears, where the transmission with an unhooked TV cable will not even shift.
I'm surprised the TH180 (or as it was known here in Australia as the Tri-Matic) didn't make the list. Fine behind a four cylinder or weak 6 cyclinder but as soon as it was put behind even a low output v8 it became a Traumatic rather than Trimatic!
And still " Traumatic " behind a 202 , especially if towing , and when combined with the sixes reputation for , blowing the tops off pistons, shearing the gear off the distributor, the fibre camshaft gear falling apart, the harmonic balancer rubber disintegrating , axles snapping , and thirsty with lackluster power , what a great deal .😂
@@garycamara9955 Trimatic's were used in Australian Holdens , but it would appear from the comments that they were also in America under a different name T180? , I'm not sure.
@@barrycuda3769 never heard of s T180 either. But I generally ignore automatic transmissions. I like a more performance car. Performance cars need sn actual transmission.
My first car was a 1977 Chevy Impala 2-door with a transplanted 350 c.i. 4-bolt main/4-bbl Quadrajet engine from a van, but they didn't change the transmission, which happened to be a TH200. Being an 18-year-old kid, I did not treat it kindly, so in the almost 4 years I owned it, I went through 2 of those transmissions. I later learned that a short-tail TH350 is the exact same length and is a direct swap. I kind of wish I would have known that in the early 1990s. It was still a fun car, as I could smoke Mustangs of the era off the line, but it did only get 10 MPG on a good day. Thankfully, this was the time of sub-$1 gas, so no big deal.
Had a Rotohydromatic 375 in my 1964 Pontiac Catalina 2+2. I did have one burn up, however I really didn't notice the drivability problems you described.
The Slim Jim was awful. I owned a ‘64 Grand Prix with one. The spectacular drop in RPM on the 1-2 upshift is jarring, as is the jump in RPM on the 2-1 downshift. Even in the ‘70s, it was hard to find a transmission shop that would work on them (and knew how to).
I've been reading the comments on others that have or have had the thm 200 metric and I've listened to your take on it....i agree 100 % but i ended up with one free from a 77 Caprice coupe that came with a very worn out 305 and put a shift kit in it ( no clutch material in the pan but it had a broken accumulator spring) put the kit in it... Updated to the metal ring for the accumulator piston and have it set to the firmest shifts and it's been kicking ass behind a 230 hp 305 that I'm not exactly kind to lol.... (It's in a small block powered 83 S10 short bed regular cab) So either the one i have was a rebuilt unit not long before the Caprice gave up or i just got lucky lol... Keep up the videos man... Love what ya do!
I had to figure out that tcc on my 1987 caprice with the 200R4 with a custom after market vacuum switch I installed on the intake manifold,it had a small Allen key for adjustment,after plugging off the break pedal vacuum tcc switch the transmission worked awesome just with this vacuum/electric switch.
My two worst. 1978 Grand Prix. It had to exceed 45 mph to upshift from 2 to 3. The dealer insisted that was normal. I got really pissed around the 4th visit to the dealer and insisted they show me the service bulletins. One bulletin said the cure was to remove a valve (I don't remember what precisely). After that its shifts were reasonable. The other was in a 1979 Cutlass. Tranny failed at about 60,000 miles. The rebuild was rough and failed in month 13. The replacement for the rebuild had to exceed 20 mph to shift from 1 to 2. After those two I stayed away from GM for a decade. Neither of these was abused. I've always driven like an old man, and I've never had another transmission problem among 20 new cars across half a dozen makes.
We had a '92 Cavalier with sticking lockup solenoid. Dealer seemed stunned that I would ask them to simply disconnect it. The car was worth $500 at best and I think they quoted at least that to fix it.
My parents had a 92 grand am, when we started having problems with the lockup selinoid we wired it to a switch so we could manually turn it on and off.
the roto- hydramatic was a harsh shifting transmission from shifting from 1st to2nd shift, also , it was not designed to be hot rodded either. there was a break away coupling on the output shaft, and if you snapped it, you were not going anywhere, it could be replaced without removing the transmission from the car. I did have a 1978 pontiac with a th200 transmission in it , but I never abused it either, and never had any troubles with it. the early th700 4 speed transmissions did have "O" ring seals blow out at the oil pump, and cause the transmission not to move the vehicle
Interesting. I've owned many GM cars over the past 40 years, and my dad owned many before that, but we somehow managed to avoid all these "worst" GM automatics. We had a 1971 Biscayne with the Turbo350, we had 1992 and 2000 Bonnevilles with the 4-speed, and I've had several Chevy pick-ups with 4- and 6-speed THM, and they've all been great. Just lucky, I guess!
About the lock-up solenoids, I used to have to shift into neutral while coasting towards a light in order to stop, and would often have trouble dropping into drive and pulling away without killing the engine in one of my parent's GMs, back in the day.
The fluid change helped my 2015 Yukon Denali. It solved the washboard condition but It still had rough shifts. Really hard for my 16 year old to learn with. That was the main reason I traded it. It did seem durable though and towed trailers really well.
I'm convinced that the 700R4 was a conspiracy from GM to keep rebuild shops in business. They put a throttle valve cable on it, then told everyone different instructions on how to adjust it properly. Some were told to adjust it correctly and some weren't, and both sides argue about it constantly to this day so that no one but rebuild shops will ever know for sure exactly how to do it. Old-timers thought cables meant adjusting shift points, so they made the TV cable control the main fluid pressure to the transmission instead, then LAUGHED AND LAUGHED as seasoned mechanics destroyed their transmissions left and right. Then they put a little solenoid in it that actuates the torque converter lockup and did the same thing, telling some people to connect it to a brake switch and others to just wire it straight to ignition power. When people started getting too wise to it, they added two more wires into the mix and no one could ever agree on what they should be used for again. Installing a 700R4 while trying to get a straight answer on anything is just a flip of a coin. Will you get lucky, and drive happily along for years to come? Or will you be informed by the wrong crowd, and have to spend thousands of dollars at the rebuild shop? You never know, but one thing is guaranteed: that transmission shop owner is going to have one cushy retirement.
Agree on the Slim Jim’s but you forgot the two very worst. Buick’s 1961-1963 Dual Paths and the miserable Turboglides that Chevy used from 1957-1961. These were so bad that most were converted to Powerglides. Transmission shops HATED these two transmissions!
You broke my heart about the early sixties transmissions. I love 57-63 GM products. I found hydromatics to be very reliable but I had a 63 Bonneville so it didn't have the trans yer speaking of.
For automatic transmission work, I recommend Key Diesel and Auto Service in Ingham county, run by my friend. I’m guessing you’re around an hour to 90 minutes away. They do all sorts of auto service involving transmission rebuilds and modifications, work on heavy duty trucks and normal cars.
Metric 200, when upgraded with stronger internals, would handle mid HP BBC without a sweat. Once upon a time, I owned an '85 Monte Carlo that was ex-FBI surveillance fleet rig (F41 suspension only option) that had burned through FOUR 305 (not HO) engines in
The metric 200 and 180 transmission was better than the junk they installed in the 2000 through 2005 Chevy Impala. I had all three transmissions, and the Impala's transmission quit at 63 000 to 70,000 miles. Happened on not one but 2 Impala's. The Metric 200 and 180 transmissions went to almost 100,000 miles before a new transmission was needed.
In 1968, I ordered a new custom camaro SS396 375 hp. from the factory. I wanted a 4 speed Muncie manual and I read that the Muncie M22 (rock crusher) was the best 4 speed to get at that time for that car. The salesman argued with me for about an hour saying that transmission was not in his order catalog. I finally talked to the sales manager and he found the option in his order book so I ordered one for several hundred dollars, extra. When I got the car, I found the transmission to be indestructible with just a slight whine in operation.
I grew up in the early 70's and, my father being a Chevy man, I had a lot of ride time with the Turbo Hydromatics, and yes, when you're used to those transmissions, the Ford C4 shifts are, to put it mildly, noticeable.
Great info especially for folks looking to get into some of the cars mentioned as a first time collector. I absolutely love the TH350 as well as the 400! I also want to say that of the current crop of 8 speed transmissions the the ZF 8 speed is an amazing unit! Why GM decided to try to build their own makes no sense as the ZF so well sorted that it is among my favorite automatics and maybe #1.
The 8 speed in my wife’s 2016 Yukon XL Denali is THE WORST transmission we’ve ever had. At 63,000 miles it’s crap. And I went through 3 PowerGlides in my 63 Impala Sport Coupe back in the late 60s. Seems that flooring a 327 while in neutral then jamming it into L was not the greatest choice for longevity. Back then a good junkyard PG was 50 bucks. Most fun you could have with your pants on for a 16 year old.
You omitted undoubtedly the worst transmission ever made - the Turboglide. It was a three speed non-shifting transmission. It had a complex torque converter with three turbines connected to three input shafts located one inside each other, and three stators. The input shafts splined to different locations in the gear train. To save money they used cone clutches. The transmission design began in 1952, I believe, to be used with the 216 cu. in. 6 cylinder cast iron wonder engine, Chevrolet’s only engine at the time. By the time the transmission design was finished it was 1957. Some marketing genius decided to pair it in the 1958 Impala with their new 348 cu. in. V-8. There was no way those cone clutches could handle the torque. Many cars never made it off the showroom floor. There was a factory fix within one week of introduction, another after three weeks, etc. etc. After a while, Chevrolet offered to replace it with a 2-speed powerglide for $75.00. Chevrolet continued refining the design and, by 1961, it was considered a pretty good transmission. But by that time nobody would buy it. This transmission should be No. One on your list. You might want to research it.
My friend bought a nearly mint 64 Pontiac GP off some old guy and the transmission seemed like it would go first to fourth because it would bog the 421 cubic inch engine way down but the engine had enough torque to pull it ok. I always thought it was odd or something was out of adjustment, but this video explains it all.
I just finished rebuilding a 1956 Cadillac Jetaway transmission for a customer. What a pain compared to modern transmissions. Mostly because they're hand-fitted. That, and of course I wasn't the first person in there, and the previous guys had beaten the fluid coupling very badly. Most parts were available but were very expensive. A lot of things could be put in backwards. Seems to work fine now, but putting it together was a case of two steps forward one step back.
That 8 speed 8L90 just a horrible transmission with an endless list of customer complaints. Thank goodness the GRX 10L80 10 speed came along and saved the day! An amazing transmission that reminds me of the great shifting of those old TH400 and TH350's.
The roto-hydramatic or slim jim did not have a torque converter. Had a little stubby splined input shaft that plugged into the spring loaded dampener on the flywheel called the flex plate. The early turbo hydramatic 400 had what was called the variable pitch stator and I think that's what you're referring to.
Thanks for the info. I just found out my 81 grand Prix has 4.3 engine TH200C transmission it came from a salvage yard it was replaced in 1990 runs good, I think! the car is been in the garage for more than 30 years, it suppose to have a 250 or 350 according to O'reileys auto parts. if it goes bad, gonna try to find the right one and pay to have it rebuild
I owned an 89' Caprice with a 200R4 trans in it and the torque converter would not unlock after driving it on the freeway. I never knew what was causing it but, I would have to manually downshift the trans after coming off the freeway and if I had to come to a complete stop, I would just bump it into neutral until the light changed. To take back off I would just do a light neutral drop to keep from killing the engine lol. I bought the car from an old man for $600 and drove it over 100k like that.
I’ve had several GM vehicles, ranging from a 1962 Oldsmobile Starfire to a 2003 Buick Regal GS. The best trans was the TH400 in a ‘68 GTO. It always shifted beautifully, even squealing the tires in full power 1st to 2nd shifts. And it never failed. The rotohydromatic in the Starfire was terrible. I didn’t think they could get worse, until decades later when I experienced the 4T65E in an ‘03 Buick. Mushy, indecisive, and with a terrible design decision of disengaging the torque converter clutch as soon as you let off the gas. Because of the tranny design, my diesel pickup had much better engine braking than this thing. Also, with only 130k, it was on the verge of breaking when I sold the car-the car wasn’t worth enough to me to pay all that money for a new, crappy transmission.
1962 Pontiac LeMans had an engine that was 1/2 of a 326 V8, a 4 cylinder. mated to an all new 2 speed trans-axle. The upper gear quit on me and I drove home from Niagara Falls to Pittsburgh in low gear shifting to neutral at speed and coasting all the way home. A transmission shop near me couldn't fix it so it sat. I started stealing my own car out of their lot every weekend. I traded it in, as-is.
The thm400 had an electrical detent valve to dump balanced pressure and increase line pressure to the shift valves, making the transmission shift later/longer. Plus increasing the clamping force of the clutch packs. TV cable on a thm350/200 did the same thing, just mechanically. 😊
A THM 350 used both modulator and tv cable. I built transmissions for years. I saw a 87 440t4 original with 350,000 miles. They needed a few expensive parts to upgrade, then like most of these, they would last and work well.
I had a 63 Olds and it felt like it skipped second. A tech explained that second was similar to a Turboglide and “they just do that”. The car consistently got 20 mpg with a high compression 2 barrel 394. I’d say replacing one of these in a Grand Prix would be an acceptable mod, even if the floor has to be modified.
The Rotohydramatic was so bad that DeLorean bought Ford transmissions for the '63 and '64 Pontiacs, much to his bosses consternation. My father put THREE of them into his 1961 Catalina during the 4 years and 90,000 miles he had the car!
I had a TH200 in my 1986 Cutlass Supreme with an Olds 307. The transmission died around the 70k mark and I wanted to put a TH350 in the car but the transmission shop said he could build the 200 for less than a 350 and make it bulletproof. The sun shell was replaced with one from a TH350 and the soft parts were of better quality. I put over 200k miles on that car and never another issue with its transmission.
@@RareClassicCars GM actually gets credit for inventing that word... They must have regretted it soon after. I had a mid 80s X-car rental in Metro Detroit once... 2.5L Iron Duke 4-cylinder THM125C. Chuggled every time I coasted down to ~25 mph. What a POS!
I work at a GM dealership and yeah I'm more than familiar with how bad the 8 speed shifts. I can always tell whenever a truck has the 8 speed because of it's terrible shifting especially 1-2 and of course the torque converter shudder problems which the new updated fluid almost always fixes (in my experience). Really an abysmal transmission in terms of shift performance. I don't know on reliability because I don't work on transmissions outside of some basic stuff.
Glad that my parents 62 Chevy II and 64 Impala wagon both had Power Glides. Not the greatest but never a problem with either transmission wise. Still miss the 327 Rochester 4 barrel in the Impala.
The obvious pattern is that GM doesn't have all of the problems worked out when they introduce new transmissions . The best transmissions all were problematic in the beginning. This problem continues today.
Actually, the PowerGlide used both a modulator & mechanical throttle control for the same reasons: Mod for pressure response and linkage for shift points.
The GM 200 metric transmission was the worst transmission ever!!! I bought a new Caprice Classic and the differential went out at 15000 miles then at 40,000 the 200 transmission went out. Had to have it rebuilt twice before 80.000 and it was going bad again when I traded it. There was a big lawsuit on GM for that transmission. Of course the Lawyers made all of the money off of it and the consumer got nothing, I promised myself not to buy another GM product after that.
I had a 78 Grand Prix which I grew to hate, partly because the first transmission, a TH 200, failed after about 20,000 miles. Foolishly, after the Grand Prix, I gave GM one more chance and bought an 89 Olds Cutlass Ciera, which was my third GM car. It had a number of problems too. After that, I swore I would never buy a GM vehicle again, and I have stuck to that oath. In listening to Scotty Kilmer every day, I'm thinking that if I buy another vehicle, it just might have to be a Toyota.
My brother and I, had a '57 Cadillac. It had a 4 speed hydromatic By '64 Cadillac had a 3 speed hydromatic. GM was thinking more horsepower was better than a 4 speed hydromatic.
I had a 1986 Pontiac Bonneville with a THM 440T4 . I got over 200k from that transmission. It always shifted a little weird. But it never died. But the 200THM was totally junk. We exchanged boatloads of them. A lot of them failed at 50k or less.
Until recently we had a 62 394 Slim Jim 4 Barrel and it clunked enough. Compared to the 61 Coupe Deville with the hyrdamatic, the slim jim seemed like junk. What clunked more than those was a Jetway 2 speed slowing down back into first felt like the unit was going to come out of the tunnel each and everytime. Both of them were better than a later FMX which were just miserable iron case nightmares. C4s are super in everyway, never figured out a reason for an FMX to even exist.
btw, The Salt Institute was formed by Detroit automakers to promote the salting of roads - the reason was salt destroyed cars and spurred their replacement
Salt does indeed kill. I believe it is the number one reason cars need to be junked after a few years in daily drive use. Also the extremely high salt content put into American food is,in my opinion,part of the reason for the national high levels of high blood pressure across the population.
My favorite GM transmissions is the 4L80E being that I'm also a Mopar guy I know the A604 is going to be 1st on the list of worst Chrysler transmissions.
@@billyjoejimbob56 and the automatic transmissions behind the Cummins engines (47RH/47RE/48RE/68RE). Those couldn’t handle the torque of the Cummins engines.
Say it with me….200-4-R 700-R-4. The latter letter & number are reversed on the two transmissions. By the way, the 700R4 was unreliable in the beginning. I had a later one, however, that was great. I’ve also had good luck with the 200 & 2004R. There is no 200-R-4.
I believe I heard you say you currently have a Cadillac diesel. I searched your videos but didn't see a review. If you still have it, and the weather is good, would you mind doing a review and walk around? Great videos. Thanks!
Cadillac Diesel might have used a better transmission than some other cars that had the Olds built 350 Diesel (THM 350 instead of THM 200/250) also the engine might have had a better quality inspection or been built in a different run on the factory floor than the general purpose engines used in the lessor GM car brands.
Yes the TCC was a problem on the 125C transmission but I didn't have a failure on the 2 Celebrity's I had and both went more than 200,000 miles. But it did fail on my grandma's 89 6000 at about 40,000 miles.
I had a an 85 Olds 98 and 1st transmission went out at 12k and the second went out at 55k. I traded it that point. Years later a GM guy said they used to tell customers that had some bad metal.
6T70 prior to 2009 often had weak wave plates that caused catastrophic failure. That was a 6-speed model created jointly with ford. Ironically, the ford models were a lot more reliable. I'm running a 6F15, which I hope lasts awhile.
The ZF 6 speeds (6HP26) also suffered from the "rear end hit" feel from 2 to 1 at stops. Sonnax zip kits seem to fix that issue, did for mine at least. Otherwise a wonderful box that was used in a number of vehicles, and made under license by Ford and maybe others. Have there been any aftermarket upgrades for any of these units in your list?
The only transmission that quit on me, they had some real junk. Ford C6 the only transmission that never gave me a problem strongest transmission ever built
The repair for this transmission was to replace it with a power-glide, the slim-jim could be replaced by jet-away. Ford transmissions lasted due to the more harsh shift by not sliding clutch packs during shifts. Chrysler transmissions were the best with the 904 and 727 aluminum case models during this time.
NOT THE old cast iron 4 speed hydro it was the jetaway turbo hydromatic was later the ones between were junk Ford AOD had similar torque converter elimination mechanical lock up when shifting
It has to be whatever transmission is in the 1989 Toyota Supra, I am on the third one, still not working right, If only I could fit a Dodge A500 4speed overdrive in there
I didn't watch the whole video Just saw this comment turbo 350 and 400 3sp had kick down shift cable. 700r OD has the throttle valve pressure cable. TV cable
I helped my dad rebuild the Roto-Hydramatic in my grandmothers 62 Olds around 1968 or so. Man that thing had a lot of parts! But when we put it back together it seem to be fine for the 6 or 7 years she continued to drive it. They did have a very odd method of operation though. I will confess to having a real soft spot for the post 1956 Buick Dynaflows which I thought were great transmissions after they started using the dual stators with the switch pitch.
i think the variable pich torque converter is 👍idea add in a way of freewheeling the stator or change its rpm speed compared to the case/shell RMP. why its not use more im not sure ( as most i know about is fixed piched with drawback's and a sprag that can be design replaced with something better to change its speed & torque vs all or nothing and it might be a way of doing over drive gearing too boot ) but modern jet engines use that trick a lot so it should work in oil just as good as air. rc-car's is right the TC solenoid does go bad in the 90's-mid 2000's caddy's i got more complaints of it not engaging ( nocking 34 mpg to about 16mpg @ 65MPH~ 1800engine rpm normally to 2500~ and yes it's more wair and tair so it does need tlc or run the risk of Windows 😉 as i have seen someone do that after putting it off for 90+ morning's commute/trips ) then lock-up/failed TC as heavyweight loads ( some people still use big sedans for towing and gardening and i probably will be forced into to doing that with my 2-gen charger as well as my 80's 1-ton K15 truck needs heavy TLC/restoration work or house stuff and my car right now is getting my TLC first 😑) or hot days can make it over heat and fail and id remove the transmission case to replace the TC ect but not to bad % of R&R money wise/reputation and using a better trans cooler and R&R-maintenance at fairly reasonable regular intervals will help and im glad i skipped using the 8-speed automatic as RC-car's was saying its not great and in a hotrod/charger more money and headache from turning the TCM ect. even if there's a kit to do it with a BBM/hemi makes my TR6070 a better choice ( evan if it's more work upfront but rewarding later on ) thanks for warning / reminding me
@@michaelbenardo5695 The 4 speed Dual Coupling Hydramatic will not fit in a 61 - 64 Catalina or Grand Prix. Only the Bonnevilles and Star Chiefs. Reason being the floor hump for the trans is smaller for the Catalina and Grand Prix. I tried it, the big hydramatic hit the floor board and the trans needed another 3 inches before the crossmember could be installed. You would have to change or modify the floor pan.
GM is famous for letting the customer sort their problems out for them, Then they perfect it and the next year they kill it. Same can be said for their Engines!
4T60E was notorious for destroying the reverse reaction drum or "stove pipe" so much that aftermarket companies were offering hardened versions of it. This really was a big problem when mated to the LQ1 3.4L DOHC engine in the GTP and Lumina possibly due to the high torque the engine could deliver at high RPMs. In fact, I remember reading about the development of the LQ1 saying GM initially intended it to deliver 250 HP or something crazy like that but had to scale it back due to transmission reliability issues.
Ah, the 4t60 and the 65, the weak point of the platform I love dearly. I'm trying to build my GTP up for more power and I already know that glass transmission is going to give me some trouble.
Great video fella, one GM transmission that didn’t make the list and was abysmal was the 4T65EV/GT which set fire to many Volvo XC90s with the I6 engine.
I don't know why I like your videos but you have a real talent with the spoken word. No hype, just communication. I had a 1980 Malibu with the Metric 200 ? transmission. It was a fleet car. It had the lockup issue which I fixed by unplugging it. When it was time to get a new car, at 50,000 miles, the leasing company asked me when the transmission was replaced. I told them it had not been. The lady said, "you must be mistaken. ALL of these cars have had the transmission replaced." I had a 1979 Malibu before that one and it had a transmission replaced at 35,000 miles. That car was driven by another person before I got it. Having said that, the Malibu Classic hardtop was a great car otherwise. No power but I live in flat country.
Had a 1980 Buick Century with the 231 V6, THM200 and no lockup. Also a fleet car... lots of highway miles... 62,000 in two years. Transmission survived, barely.
Another very compelling video. Having rebuilt and destroyed a number of GM4L70E transmissions and spent way too much time in the Transtar and Sonnax catalogs, it's a topic near and dear to my heart.
Very educational and enjoyable, Adam! You have definitely created a very watchable channel appealing to many of us who fondly remember daily drivers of the past. Thank you! 👍👍👍
I seem to remember the TV & modulator were standard design for most of GM's autos (powerglide, th350, 400, etc). Only later did they try to simplify with a TV only, which is one reason the TH200 has poor shifts. Also, owners should be careful if disconnecting the TCC valve as a long term solution. On some models lockup does play a role in cooling. If the TCC is slipping on the highway you could end up cooking the fluid.
Dealing with something like that in my 1981 Bonneville with the 200-4R. The Lock up isnt working because according the the code the vehicle speed sensor is not working so the computer wont lock the torque converter. I'm currently until I can deal with this better driving it in 3rd for the very reason you just mentioned. I dont want to ruin the transmission by overheating it by running it in overdrive.
With any automatic transmission, use of an auxiliary aftermarket transmission cooler will extend the life of the transmission. The cooler it runs, the less fluid degradation there is, even with modern synthetic fluids such as Dexron VI or Mercon V or LV Some vehicles are equipped with auxiliary coolers from the factory, but installation of a larger capacity aftermarket cooler is just added insurance against premature failure, especially behind a high performance engine or when a vehicle is frequently used for towing or hauling heavy loads.
@@markschommer7407 Pretty sure the 2004r wasn't being equipped in '81, I bet yours is a 3-speed th-200c. The speed sensor would be on the back of the speedometer, senses rotation of speedo cable. Not a big deal really if it's a th200c, th250c or th350c, these were all 3-speed. The 4-speed (overdrive) WILL overheat if tq converter lockup isn't working. Lockup occurred above either 35mph, or 45mph in the case of california emissions. The th-200c is sensitive to tv cable adjustment, make sure it's right else it'l burn the clutches in just a few miles.
The th350 had a kickdown cable, it wasn't a tv cable and misadjustment didn't lead to immediate damage. Th400 had electric kickdown, from a switch on the throttle cable.
Great chat. I remember driving a 63 Starfire and being disappointed with the upshift to second gear. Also, your comment on the C6 shift is very true. My 428 powered T-Bird would chirp the tires between both upshifts during hard acceleration.
I had a 63 Olds Starfire it was rough shifting , it had super drive , on flat ground it was fast it weighted in at 4200 pounds , my father bought this for me as my first car at 17 , l drove it from 1970 - 75 great car , great memories thanks for your videos 😎👍 Doug
Being an old Pontiac man, I had a 62 and a 63 Catalinas. If you lived in a flat area, it was almost ok. But I lived in a hilly state and they were total crap. When I got a 70 Cat with a measally 350 2 bbl, I could not believe what a night and day difference. It ran circles around the 389's.
Great presentation again Adam! I don't know what GM was thinking when they began putting the Metric 200 transmissions into larger V8 powered cars. My uncle went through 3 of them in his 81 Caprice coupe back in the day. Even the 82 Trans Am and Camaro had a turbo 200 in it. My high school shop teacher did a transmission swap demo in class on his 82 Trans Am when I was in high school. A Turbo 350 went in it's place. Comparing the size of the output shafts against each other (200 vs 350), it was pretty clear which was the stronger and better choice. Along with the Rotomatic, Chevrolet's Turboglide (1957-62) was complete disaster.
The 58 - 59 Buick Flight-Pitch DynaFlow, similar to Chevy's TurboGlide but larger, was not the greatest either. It wasn't so much unreliable as it was so slippery that it made the "regular" Dynaflop seem fantastic by comparison. GM, unfortunately, has done some pretty stupid things, things that the haters immediately latched onto.
The 82 trans am and z28 with the crossfire engine-th200 trans was an INTERESTING combo. I know it's fiction but a season 1 episode of knight rider kitt towed a car and broke the alpha circuit in the transmission.
As I recall when the Roto Hydramatic AKA Jetaway Hydramatic was released. I red an article probably in Popular science, or Popular mechanics in the late '60s that GM would not provide repair kits or detailed manuals, as the new transmission was so reliable that in the most unlikely event of a failure that you would have to use a factory rebuilt unit. Seems that it was one of the worst up to that point. In the late '50s there was the Turbo Powerglide. (I think that is what it was called). JC Whitney used to sell a conversion kit to install a regular 2 speed Power Glide. A neighbor teenager had a lawn service so he could save enough to buy every teen age boy's dream in '55 to have a '55 rocket 88 Olds. When it was finally delivered after a long wait it had a Buick Dyna-flop. Did not accept delivery. Although not GM I think that Packard with their "Ultramatic" had probably the most un reliable transmissions. From what I understand it was a factory philosophy of NIH. Depended on precision bushings with no seal rings, the clutch steels were burnt blue like a hand from an antique watch.. Ford had the 70s C4 Clutches fail just out of warranty at 12k. Then the C5 which would suddenly just stop working. I have no idea what the problem was. It was so bad that my employer, Motorola at the time forbid us from buying a vehicle with a C5.
The jetaway 315 is the last revision of the old hydramatic 4 speed. Dual coupling 4 speed used in Cadillac up to a few units in 64’. The slim Jim is the turd you’re describing. Olds and Pontiac.
I had a 1992 Lumina coupe with the 3T40 and the lockup solenoid got stuck on it. I replaced it myself and it was a surprisingly easy fix! I only paid $400 for the car at the time so I didn't care if it was successful or not. But anyways the 3t40 coupled with the 3.1L MPFI V6 was decent. Good passing power for he most part but man was second gear LONG!
I had a 92 Beretta with a lockup solenoid that started sticking. When I looked at the procedure for repairing it, it seemed like the whole left side of the car would have to come apart! I just unhooked it and drove it like that until it finally went to the scrapyard. I put more than 100,000 miles on that car over 7 years, it really did me right even though it completely fell apart by the end. I never got a Check Engine light and only lost 1 or 2 mpg for disconnecting the solenoid.
“…you enjoy forms of torture!” 😂 YES, I have rebuilt ONE of those roto-messes and NEVER AGAIN! Very torturous indeed! Took me awhile but I’m finally getting around to watching/listening to this & “best transmissions” porch chat vid’s. So glad you mentioned that incredibly well engineered 425 setup. Was a very interesting combination of tech; I own two 1955 Buick Super Riviera’s, both w/“Switch Pitch” or, as was newly called then, “Variable Pitch” Dynaflow! Also had inherited my grandfather’s 1975 GMC Palm Beach Motorhome with 455 Olds front wheel drive trans setup.. loved that motorhome
![[UA] Eternal Fire проти NAVI | EPL Season 20 Malta](http://i.ytimg.com/vi/chvlsDygrZM/mqdefault.jpg)
I remember attending a Chevy/GM event at the Indy 500....all the new cars were on display including engineering cutaways. At the automatic transmission display, I made a comment that my BMW had a GM transmission..if I recall my E46 3 Series Touring used a version of GMs 5L50E..a GM employee at the display said..."well that is one thing we do well."
The one clinker we had was on our 1979 Cutlass with the 260 V8....we had the THM-200 which dropped reverse at 78,000 miles. That was a month to remember....the transmission went out in the Cutlass...then my Dad had a heart issue and was hospitalized at the age of 49. So I remember visiting dad at the hospital and talking with the transmission shop and arranging for the transmission to be rebuilt. Some months later, we did get a class action lawsuit notice about a settlement involving the THM-200...but we apparently exceeded the mileage cap.
Some years later, on an episode of the Simpsons, Homer pulls into a gas station and asks the attendant if he is hearing a funny noise...the attendant responds, "I think you're having a heart attack." Homer response, "Phew, for a moment there, I thought it was my transmission." I thought of Dad as he had both in the same month.
He recovered....and to celebrate, he ended up buying a new boat the following month.....and towed it home using the Cutlass.....
Excellent!
At one time, Lincoln used a Hydra-matic as did Rolls Royce and a few others.
Had a Friend who had a Cutlass with the 260 V8 and the TH200. The transmission went out. So he took it to a local Austin, TX Transmission Shop. The Shop Owner told him that yes, they could rebuild the transmission. But why rebuild a p.o.s. For the same cost they put a TH350 and geared it for the speedometer. It was like night and day when he got the car back.
I bought my wife a used 78 Cutlass with about 25K miles it was loaded sunroof and all. Both the Chevy 305 eng and the TH200 failed. I got a check from GM and bought a Targetmaster 350 and a rebuilt TH350 and we kept that car for almost 20 years
Was he a smoker? That's kind of early for heart issues.
I am a service manager for a national used car retailer, and the 14 up 8 spd transmissions are crud. The "Magic Fluid" flush can stave off internal repairs for a time...but the 1-2 upshift and 2-1 downshift clunks come back and destroys internals. Nice vid!
I work at a GM shop and I HATE the 8spd. I can always immediately tell when a truck has it because of that 1-2 shift and of course the plague torque converter shudder problems.
Fascinating. Keep up the Porch Chats™, Adam, loving this "Best & Worst" series.
Who will touch it? LOL I will---any of those (except the stamped planetary carrier THM 200) is simpler and better than the newer electronic POS transmissions.
Just rebuilt 2 old Fordomatics, both in 1957 Thunderbirds. Next one up is a Ford AOD upgraded with 4R70w wide ratio planetary set, and then a C6 with extra clutches AND an E4OD wide ratio planetary set.
We used to chuck the THM 200s into the scrap pile and replace them with THM 350s
Agreed
The THM200? Garbage. My mom had one in a new ‘78 Malibu Classic with the 305, and it had problems from the word go. It was in and out of two dealer’s shops even before it was a year old. One dealer suggested annual fluid changes (!). After a few years of dealers dinking with it (and the class action lawsuit which got her something like $50), the case support (the planetary carrier?) broke, then it wouldn’t shift from second to third unless you backed completely off the throttle. A conversion to a rebuilt Turbo 350 by a local indy transmission shop (they were covered up with THM200 problems, and performing 350 conversions) finally fixed it.
These are great!
@donreinke5863 TH200s I've heard being referred to as "GM Coffee Can Transmissions". Lol that's accurate 😆
Great stuff not a bunch of music or flash just a porch an the day an something to talk about.... simply great stuff 👍👍👍👍
TH 350`s had a modulator, the TV cable was for kickdown/passing gear purposes only. The TH 400 had a modulator as you mentioned but it utilized an electrical kickdown/passing gear, they both performed the same function.
The TH 200 was a very good transmission if GM had left it in the Chevette like it was designed for, it was ok even for lightweight V6 applications but they chose to put it in everything across the board which was a very bad decision.
Most people aren`t as picky about a silky smooth shift as you are (no offense). Stiffer springs could be added to the servo`s and accumulator`s to soften some of that up if a person wanted to modify things. I never liked any lockup convertor, they only have one tiny clutch disc inside of them. I got old, my memory is starting to fade bad.
You`re very knowledgeable and speak pleasantly and your videos are very entertaining. I`m new and have been on a binge watching your content.
Thank you for all your efforts. :)
I always had great luck with TH 350's; the older ones would handle more torque than what they typically got credit for. The governors are also pretty simple to modify in order to change the shift points to coincide with more torque once the engine had been modified. TCI shift kit to firm up the shifts, grind most of the weight off the governor spring pads and then start messing with different colored springs... with a little experimenting you could usually get the shift points pretty close to where you wanted them. Great transmission. I'm looking forward to see what Adam has to say when he does GM's best list.
@@remingtonwingmaster6929 I would imagine the 400, 350 and Powerglide will be on that list. We`ll see. :)
Thanks for sharing willy :)
Not related exactly but I like the th350 in my 70 buick lesabre. Smooth and sounds nice too.
I had a bunch of Chevetts.and never had a transmission problem. They were good where they belonged.
I've got a TH200 in my 82 Camaro. I read about the issues they were having with the larger cars so right after I paid off the car. (4yrs.) I noticed a "slip" and carried it to AAMCO to get it checked. They said a bushing went bad and gave me prices and warranty options. At the top end was $200/lifetime guarantee. Knowing what I had , I went for the lifetime warranty. That transmission has been rebuilt 4 separate times. I asked why we were having so many issues and the mechanic admitted that it was designed for the 4cyl engine and couldn't take the torque of a V8.
After the second rebuild asked why we couldn't upgrade to a better transmission. GM stopped installing it in the F bodies but the mechanic refused saying that was the transmission that was warranted and that was the transmission that was going to be rebuilt.
So every 4 years or 80K miles they would rebuild it. That was the best $200 I ever spent.
Another great video Adam. Some of these have been mentioned below, but don't forget the '58-'59 Buick Triple Turbine Flight Pitch Dynaflow (MUCH less reliable than the standard twin-turbine Dynaflow that was available at the same time). The '57-'61 Chevy Turboglide was based on the same principles (variable pitch stators instead of shifts). Many of the Turboglides got replaced with Powerglides. The Buick Dual Path Dynaflow used only in the '61-'63 Special/Skylark was strange in that it had planetary gears inside of the torque converter. Not sure about reliability on those, but it is a strange design.
Reliability of the Dual Path Dynaflow? In production for three years, never to be seen again? There's your answer!
I remember that odd-ball. Never heard anything much about it, but it wasn't made for long.
Actually, the turbo 350 does have a vacuum modulator valve, as well as a passing gear cable. The difference between a passing gear cable and a throttle valve cable is the transmission with a disconnected passing gear cable will still have a normal life span and shift gears, where the transmission with an unhooked TV cable will not even shift.
There's no such thing as a "passing gear." It's just a downshift to a lower gear.
@@matthewhardy8133 Yes, but we all called it "passing gear" in the old days, because the primary reason for downshifting was to pass.
I'm surprised the TH180 (or as it was known here in Australia as the Tri-Matic) didn't make the list. Fine behind a four cylinder or weak 6 cyclinder but as soon as it was put behind even a low output v8 it became a Traumatic rather than Trimatic!
And still " Traumatic " behind a 202 , especially if towing , and when combined with the sixes reputation for , blowing the tops off pistons, shearing the gear off the distributor, the fibre camshaft gear falling apart, the harmonic balancer rubber disintegrating , axles snapping , and thirsty with lackluster power , what a great deal .😂
What is a trimatic? Never heard of it. Do you mean a th 350?
@@garycamara9955 Trimatic's were used in Australian Holdens , but it would appear from the comments that they were also in America under a different name T180? , I'm not sure.
@@barrycuda3769 most cars are V8s here accept for compacts like Falcons (some V8s) Corvairs, Valiants, and Darts.
@@barrycuda3769 never heard of s T180 either. But I generally ignore automatic transmissions. I like a more performance car. Performance cars need sn actual transmission.
My first car was a 1977 Chevy Impala 2-door with a transplanted 350 c.i. 4-bolt main/4-bbl Quadrajet engine from a van, but they didn't change the transmission, which happened to be a TH200. Being an 18-year-old kid, I did not treat it kindly, so in the almost 4 years I owned it, I went through 2 of those transmissions. I later learned that a short-tail TH350 is the exact same length and is a direct swap. I kind of wish I would have known that in the early 1990s. It was still a fun car, as I could smoke Mustangs of the era off the line, but it did only get 10 MPG on a good day. Thankfully, this was the time of sub-$1 gas, so no big deal.
Had a Rotohydromatic 375 in my 1964 Pontiac Catalina 2+2. I did have one burn up, however I really didn't notice the drivability problems you described.
The Slim Jim was awful. I owned a ‘64 Grand Prix with one. The spectacular drop in RPM on the 1-2 upshift is jarring, as is the jump in RPM on the 2-1 downshift. Even in the ‘70s, it was hard to find a transmission shop that would work on them (and knew how to).
I've been reading the comments on others that have or have had the thm 200 metric and I've listened to your take on it....i agree 100 % but i ended up with one free from a 77 Caprice coupe that came with a very worn out 305 and put a shift kit in it ( no clutch material in the pan but it had a broken accumulator spring) put the kit in it... Updated to the metal ring for the accumulator piston and have it set to the firmest shifts and it's been kicking ass behind a 230 hp 305 that I'm not exactly kind to lol.... (It's in a small block powered 83 S10 short bed regular cab) So either the one i have was a rebuilt unit not long before the Caprice gave up or i just got lucky lol... Keep up the videos man... Love what ya do!
I had to figure out that tcc on my 1987 caprice with the 200R4 with a custom after market vacuum switch I installed on the intake manifold,it had a small Allen key for adjustment,after plugging off the break pedal vacuum tcc switch the transmission worked awesome just with this vacuum/electric switch.
My two worst. 1978 Grand Prix. It had to exceed 45 mph to upshift from 2 to 3. The dealer insisted that was normal. I got really pissed around the 4th visit to the dealer and insisted they show me the service bulletins. One bulletin said the cure was to remove a valve (I don't remember what precisely). After that its shifts were reasonable.
The other was in a 1979 Cutlass. Tranny failed at about 60,000 miles. The rebuild was rough and failed in month 13. The replacement for the rebuild had to exceed 20 mph to shift from 1 to 2. After those two I stayed away from GM for a decade.
Neither of these was abused. I've always driven like an old man, and I've never had another transmission problem among 20 new cars across half a dozen makes.
I finally got to get back viewing RCC&AH. Love these spots Adam... please keep doing these.
We had a '92 Cavalier with sticking lockup solenoid. Dealer seemed stunned that I would ask them to simply disconnect it. The car was worth $500 at best and I think they quoted at least that to fix it.
My parents had a 92 grand am, when we started having problems with the lockup selinoid we wired it to a switch so we could manually turn it on and off.
the roto- hydramatic was a harsh shifting transmission from shifting from 1st to2nd shift, also , it was not designed to be hot rodded either. there was a break away coupling on the output shaft, and if you snapped it, you were not going anywhere, it could be replaced without removing the transmission from the car. I did have a 1978 pontiac with a th200 transmission in it , but I never abused it either, and never had any troubles with it. the early th700 4 speed transmissions did have "O" ring seals blow out at the oil pump, and cause the transmission not to move the vehicle
Interesting. I've owned many GM cars over the past 40 years, and my dad owned many before that, but we somehow managed to avoid all these "worst" GM automatics. We had a 1971 Biscayne with the Turbo350, we had 1992 and 2000 Bonnevilles with the 4-speed, and I've had several Chevy pick-ups with 4- and 6-speed THM, and they've all been great. Just lucky, I guess!
About the lock-up solenoids, I used to have to shift into neutral while coasting towards a light in order to stop, and would often have trouble dropping into drive and pulling away without killing the engine in one of my parent's GMs, back in the day.
The fluid change helped my 2015 Yukon Denali. It solved the washboard condition but It still had rough shifts. Really hard for my 16 year old to learn with. That was the main reason I traded it. It did seem durable though and towed trailers really well.
I really like what you’re doing…and how you’re doing it. Do keep it up.
I'm convinced that the 700R4 was a conspiracy from GM to keep rebuild shops in business. They put a throttle valve cable on it, then told everyone different instructions on how to adjust it properly. Some were told to adjust it correctly and some weren't, and both sides argue about it constantly to this day so that no one but rebuild shops will ever know for sure exactly how to do it. Old-timers thought cables meant adjusting shift points, so they made the TV cable control the main fluid pressure to the transmission instead, then LAUGHED AND LAUGHED as seasoned mechanics destroyed their transmissions left and right. Then they put a little solenoid in it that actuates the torque converter lockup and did the same thing, telling some people to connect it to a brake switch and others to just wire it straight to ignition power. When people started getting too wise to it, they added two more wires into the mix and no one could ever agree on what they should be used for again. Installing a 700R4 while trying to get a straight answer on anything is just a flip of a coin. Will you get lucky, and drive happily along for years to come? Or will you be informed by the wrong crowd, and have to spend thousands of dollars at the rebuild shop? You never know, but one thing is guaranteed: that transmission shop owner is going to have one cushy retirement.
Agree on the Slim Jim’s but you forgot the two very worst. Buick’s 1961-1963 Dual Paths and the miserable Turboglides that Chevy used from 1957-1961. These were so bad that most were converted to Powerglides. Transmission shops HATED these two transmissions!
Millions of Powerglides served us well for decades. They are used to good effect today in budget dragsters up to 1,000 hp.
You broke my heart about the early sixties transmissions. I love 57-63 GM products. I found hydromatics to be very reliable but I had a 63 Bonneville so it didn't have the trans yer speaking of.
For automatic transmission work, I recommend Key Diesel and Auto Service in Ingham county, run by my friend. I’m guessing you’re around an hour to 90 minutes away. They do all sorts of auto service involving transmission rebuilds and modifications, work on heavy duty trucks and normal cars.
Metric 200, when upgraded with stronger internals, would handle mid HP BBC without a sweat.
Once upon a time, I owned an '85 Monte Carlo that was ex-FBI surveillance fleet rig (F41 suspension only option) that had burned through FOUR 305 (not HO) engines in
The metric 200 and 180 transmission was better than the junk they installed in the 2000 through 2005 Chevy Impala. I had all three transmissions, and the Impala's transmission quit at 63 000 to 70,000 miles. Happened on not one but 2 Impala's. The Metric 200 and 180 transmissions went to almost 100,000 miles before a new transmission was needed.
Thanks for those tips. Extremely helpful!
In 1968, I ordered a new custom camaro SS396 375 hp. from the factory. I wanted a 4 speed Muncie manual and I read that the Muncie M22 (rock crusher) was the best 4 speed to get at that time for that car. The salesman argued with me for about an hour saying that transmission was not in his order catalog. I finally talked to the sales manager and he found the option in his order book so I ordered one for several hundred dollars, extra. When I got the car, I found the transmission to be indestructible with just a slight whine in operation.
I grew up in the early 70's and, my father being a Chevy man, I had a lot of ride time with the Turbo Hydromatics, and yes, when you're used to those transmissions, the Ford C4 shifts are, to put it mildly, noticeable.
Great info especially for folks looking to get into some of the cars mentioned as a first time collector. I absolutely love the TH350 as well as the 400! I also want to say that of the current crop of 8 speed transmissions the the ZF 8 speed is an amazing unit! Why GM decided to try to build their own makes no sense as the ZF so well sorted that it is among my favorite automatics and maybe #1.
The 8 speed in my wife’s 2016 Yukon XL Denali is THE WORST transmission we’ve ever had. At 63,000 miles it’s crap. And I went through 3 PowerGlides in my 63 Impala Sport Coupe back in the late 60s. Seems that flooring a 327 while in neutral then jamming it into L was not the greatest choice for longevity. Back then a good junkyard PG was 50 bucks. Most fun you could have with your pants on for a 16 year old.
You omitted undoubtedly the worst transmission ever made - the Turboglide. It was a three speed non-shifting transmission. It had a complex torque converter with three turbines connected to three input shafts located one inside each other, and three stators. The input shafts splined to different locations in the gear train. To save money they used cone clutches. The transmission design began in 1952, I believe, to be used with the 216 cu. in. 6 cylinder cast iron wonder engine, Chevrolet’s only engine at the time. By the time the transmission design was finished it was 1957.
Some marketing genius decided to pair it in the 1958 Impala with their new 348 cu. in. V-8. There was no way those cone clutches could handle the torque. Many cars never made it off the showroom floor. There was a factory fix within one week of introduction, another after three weeks, etc. etc. After a while, Chevrolet offered to replace it with a 2-speed powerglide for $75.00. Chevrolet continued refining the design and, by 1961, it was considered a pretty good transmission. But by that time nobody would buy it. This transmission should be No. One on your list. You might want to research it.
My friend bought a nearly mint 64 Pontiac GP off some old guy and the transmission seemed like it would go first to fourth because it would bog the 421 cubic inch engine way down but the engine had enough torque to pull it ok. I always thought it was odd or something was out of adjustment, but this video explains it all.
I just finished rebuilding a 1956 Cadillac Jetaway transmission for a customer. What a pain compared to modern transmissions. Mostly because they're hand-fitted. That, and of course I wasn't the first person in there, and the previous guys had beaten the fluid coupling very badly. Most parts were available but were very expensive. A lot of things could be put in backwards. Seems to work fine now, but putting it together was a case of two steps forward one step back.
That 8 speed 8L90 just a horrible transmission with an endless list of customer complaints. Thank goodness the GRX 10L80 10 speed came along and saved the day! An amazing transmission that reminds me of the great shifting of those old TH400 and TH350's.
The roto-hydramatic or slim jim did not have a torque converter. Had a little stubby splined input shaft that plugged into the spring loaded dampener on the flywheel called the flex plate. The early turbo hydramatic 400 had what was called the variable pitch stator and I think that's what you're referring to.
Concise and thorough as usual. Great video mate 👍
7 minutes into it..
Had me cracking UP ‼️ 😂
I’m feelin better about my 67 iMpala resurrection;) 👌🏼
Thanks for the info. I just found out my 81 grand Prix has 4.3 engine TH200C transmission it came from a salvage yard it was replaced in 1990 runs good, I think! the car is been in the garage for more than 30 years, it suppose to have a 250 or 350 according to O'reileys auto parts. if it goes bad, gonna try to find the right one and pay to have it rebuild
I owned an 89' Caprice with a 200R4 trans in it and the torque converter would not unlock after driving it on the freeway. I never knew what was causing it but, I would have to manually downshift the trans after coming off the freeway and if I had to come to a complete stop, I would just bump it into neutral until the light changed. To take back off I would just do a light neutral drop to keep from killing the engine lol. I bought the car from an old man for $600 and drove it over 100k like that.
I’ve had several GM vehicles, ranging from a 1962 Oldsmobile Starfire to a 2003 Buick Regal GS. The best trans was the TH400 in a ‘68 GTO. It always shifted beautifully, even squealing the tires in full power 1st to 2nd shifts. And it never failed.
The rotohydromatic in the Starfire was terrible. I didn’t think they could get worse, until decades later when I experienced the 4T65E in an ‘03 Buick. Mushy, indecisive, and with a terrible design decision of disengaging the torque converter clutch as soon as you let off the gas. Because of the tranny design, my diesel pickup had much better engine braking than this thing. Also, with only 130k, it was on the verge of breaking when I sold the car-the car wasn’t worth enough to me to pay all that money for a new, crappy transmission.
1962 Pontiac LeMans had an engine that was 1/2 of a 326 V8,
a 4 cylinder. mated to an all new 2 speed trans-axle. The upper gear quit on me and I drove home from Niagara Falls to Pittsburgh in low gear shifting to neutral at speed and coasting all the way home. A transmission shop near me couldn't fix it so it sat. I started stealing my own car out of their lot every weekend. I traded it in, as-is.
The thm400 had an electrical detent valve to dump balanced pressure and increase line pressure to the shift valves, making the transmission shift later/longer. Plus increasing the clamping force of the clutch packs.
TV cable on a thm350/200 did the same thing, just mechanically. 😊
A THM 350 used both modulator and tv cable. I built transmissions for years. I saw a 87 440t4 original with 350,000 miles. They needed a few expensive parts to upgrade, then like most of these, they would last and work well.
I had a 63 Olds and it felt like it skipped second. A tech explained that second was similar to a Turboglide and “they just do that”.
The car consistently got 20 mpg with a high compression 2 barrel 394.
I’d say replacing one of these in a Grand Prix would be an acceptable mod, even if the floor has to be modified.
The Rotohydramatic was so bad that DeLorean bought Ford transmissions for the '63 and '64 Pontiacs, much to his bosses consternation. My father put THREE of them into his 1961 Catalina during the 4 years and 90,000 miles he had the car!
I had a TH200 in my 1986 Cutlass Supreme with an Olds 307. The transmission died around the 70k mark and I wanted to put a TH350 in the car but the transmission shop said he could build the 200 for less than a 350 and make it bulletproof. The sun shell was replaced with one from a TH350 and the soft parts were of better quality. I put over 200k miles on that car and never another issue with its transmission.
The 440T4 introduced the word Chuggle to the lexicon.
Yes. My favorite diagnostic word
@@RareClassicCars GM actually gets credit for inventing that word... They must have regretted it soon after.
I had a mid 80s X-car rental in Metro Detroit once... 2.5L Iron Duke 4-cylinder THM125C. Chuggled every time I coasted down to ~25 mph. What a POS!
Adam, Did these GM transmission issues arise around the time they stopped using genuine whale oil in the transmission fluid? 😂
Nah. Wasn’t a function of that!
I work at a GM dealership and yeah I'm more than familiar with how bad the 8 speed shifts. I can always tell whenever a truck has the 8 speed because of it's terrible shifting especially 1-2 and of course the torque converter shudder problems which the new updated fluid almost always fixes (in my experience). Really an abysmal transmission in terms of shift performance. I don't know on reliability because I don't work on transmissions outside of some basic stuff.
I've got a 2022; the 1-2 shift is funky. Seems to flare between 1 and 2 when first driven in the morning....
@@kwt7667g Yeah and they all do that, you'd think GM would fix it after all of these years of that transmission being in service but nope!
If it ain't broke don't fix it, HELLO ALL U ENGINEERS OUT THERE THAT REINVENTING THE WHEEL.
Glad that my parents 62 Chevy II and 64 Impala wagon both had Power Glides. Not the greatest but never a problem with either transmission wise. Still miss the 327 Rochester 4 barrel in the Impala.
The obvious pattern is that GM doesn't have all of the problems worked out when they introduce new transmissions . The best transmissions all were problematic in the beginning. This problem continues today.
Actually, the PowerGlide used both a modulator & mechanical throttle control for the same reasons: Mod for pressure response and linkage for shift points.
The GM 200 metric transmission was the worst transmission ever!!! I bought a new Caprice Classic and the differential went out at 15000 miles then at 40,000 the 200 transmission went out. Had to have it rebuilt twice before 80.000 and it was going bad again when I traded it. There was a big lawsuit on GM for that transmission. Of course the Lawyers made all of the money off of it and the consumer got nothing, I promised myself not to buy another GM product after that.
Disable the lock up is smart.
I had a 78 Grand Prix which I grew to hate, partly because the first transmission, a TH 200, failed after about 20,000 miles. Foolishly, after the Grand Prix, I gave GM one more chance and bought an 89 Olds Cutlass Ciera, which was my third GM car. It had a number of problems too. After that, I swore I would never buy a GM vehicle again, and I have stuck to that oath. In listening to Scotty Kilmer every day, I'm thinking that if I buy another vehicle, it just might have to be a Toyota.
My brother and I, had a '57 Cadillac. It had a 4 speed hydromatic
By '64 Cadillac had a 3 speed hydromatic. GM was thinking more horsepower was better than a 4 speed hydromatic.
I had a 1986 Pontiac Bonneville with a THM 440T4 . I got over 200k from that transmission. It always shifted a little weird. But it never died. But the 200THM was totally junk. We exchanged boatloads of them. A lot of them failed at 50k or less.
Until recently we had a 62 394 Slim Jim 4 Barrel and it clunked enough. Compared to the 61 Coupe Deville with the hyrdamatic, the slim jim seemed like junk. What clunked more than those was a Jetway 2 speed slowing down back into first felt like the unit was going to come out of the tunnel each and everytime. Both of them were better than a later FMX which were just miserable iron case nightmares. C4s are super in everyway, never figured out a reason for an FMX to even exist.
btw, The Salt Institute was formed by Detroit automakers to promote the salting of roads - the reason was salt destroyed cars and spurred their replacement
Salt does indeed kill. I believe it is the number one reason cars need to be junked after a few years in daily drive use. Also the extremely high salt content put into American food is,in my opinion,part of the reason for the national high levels of high blood pressure across the population.
My favorite GM transmissions is the 4L80E being that I'm also a Mopar guy I know the A604 is going to be 1st on the list of worst Chrysler transmissions.
The A604 could do a 3 to neutral downshift when brand new. You would let up and it would find 1st or 2nd depending on the mood.
That's not fair... too easy!!! Second on the Mopar list... That wonderful JATCO CVT in the Compass and Patriot Jeeps.
@@billyjoejimbob56 and the automatic transmissions behind the Cummins engines (47RH/47RE/48RE/68RE). Those couldn’t handle the torque of the Cummins engines.
My Powerglide had that first to second klunk.
727 Torqueflite best 60s transmission hands down
The 440 T4 was not the first GM front wheel drive. The Oldsmobile Toronado and Cadillac Eldorado while not transverse were front wheel drive.
That’s why I say the first of GMs FWD, transverse 4 speed transmissions at 7:33. Never said it was their first FWD transmission.
Say it with me….200-4-R
700-R-4.
The latter letter & number are reversed on the two transmissions.
By the way, the 700R4 was unreliable in the beginning.
I had a later one, however, that was great.
I’ve also had good luck with the 200 & 2004R.
There is no 200-R-4.
I believe I heard you say you currently have a Cadillac diesel. I searched your videos but didn't see a review. If you still have it, and the weather is good, would you mind doing a review and walk around? Great videos. Thanks!
Cadillac Diesel might have used a better transmission than some other cars that had the Olds built 350 Diesel (THM 350 instead of THM 200/250) also the engine might have had a better quality inspection or been built in a different run on the factory floor than the general purpose engines used in the lessor GM car brands.
Yes the TCC was a problem on the 125C transmission but I didn't have a failure on the 2 Celebrity's I had and both went more than 200,000 miles. But it did fail on my grandma's 89 6000 at about 40,000 miles.
I had a an 85 Olds 98 and 1st transmission went out at 12k and the second went out at 55k. I traded it that point. Years later a GM guy said they used to tell customers that had some bad metal.
6T70 prior to 2009 often had weak wave plates that caused catastrophic failure. That was a 6-speed model created jointly with ford. Ironically, the ford models were a lot more reliable. I'm running a 6F15, which I hope lasts awhile.
Th400 modulator and a kick down solinoid. Th350 modulator and kick down cable TH 200 series TV cable. TH 700 is a early years problem trans
shifts are fully clutches vs bands
The ZF 6 speeds (6HP26) also suffered from the "rear end hit" feel from 2 to 1 at stops. Sonnax zip kits seem to fix that issue, did for mine at least. Otherwise a wonderful box that was used in a number of vehicles, and made under license by Ford and maybe others. Have there been any aftermarket upgrades for any of these units in your list?
GM forced Pontiac to take that lousy Olds transmission because they needed the volume - huge mistake
If my memory is correct, only the smaller Pontiacs - Chieftain/Ventura - used it. The Star Chief and Bonneville kept the 4 speed Hydra.
No mention of the 325-4L on the naughty list?
Tcc info at end great.
The only transmission that quit on me, they had some real junk. Ford C6 the only transmission that never gave me a problem strongest transmission ever built
Please keep doing the porch chats
You left out the infamous "Turbo-Glide" debuted in '57 chevrolet's version of a dyna flow. POS. GM dealer mechanics called the trouble glides.
The repair for this transmission was to replace it with a power-glide, the slim-jim could be replaced by jet-away. Ford transmissions lasted due to the more harsh shift by not sliding clutch packs during shifts.
Chrysler transmissions were the best with the 904 and 727 aluminum case models during this time.
NOT THE old cast iron 4 speed hydro it was the jetaway turbo hydromatic was later the ones between were junk Ford AOD had similar torque converter elimination mechanical lock up when shifting
Cool video I liked it. You can only unplug the lock up on 3 speeds.
I’ve done it on 4 speeds too. 325s.
It has to be whatever transmission is in the 1989 Toyota Supra, I am on the third one, still not working right,
If only I could fit a Dodge A500 4speed overdrive in there
Dude put this in a podcast on Spotify
To clarify, the TV cable on the TurboHydromatic 350 is only for kickdown, not shift points. The vacuum modulator controlled that.
Or as palooka joe admin. say
..."let me be clear" as mud 😶
The tv cable controls line pressure.
Governor pressure as well.
@@garyelkhorn2116< The 350 cable controls down shift only. The modulator controls shift points.
I didn't watch the whole video
Just saw this comment turbo 350 and 400 3sp had kick down shift cable. 700r OD has the throttle valve pressure cable. TV cable
I helped my dad rebuild the Roto-Hydramatic in my grandmothers 62 Olds around 1968 or so. Man that thing had a lot of parts! But when we put it back together it seem to be fine for the 6 or 7 years she continued to drive it. They did have a very odd method of operation though. I will confess to having a real soft spot for the post 1956 Buick Dynaflows which I thought were great transmissions after they started using the dual stators with the switch pitch.
I suspect Boz Scaggs would agree with you, assuming "Dinah Flo" wasn't actually a woman.
Boz Skaggs? I’m a bit corn-fuzed..... would that not be Frank Zappa and the infamous “Dinah-Mo-Hum”?
You got it to last? Congratulations. Many replaced it with the older 4 speed Dual Coupling HydraMatic.
i think the variable pich torque converter is 👍idea add in a way of freewheeling the stator or change its rpm speed compared to the case/shell RMP. why its not use more im not sure ( as most i know about is fixed piched with drawback's and a sprag that can be design replaced with something better to change its speed & torque vs all or nothing and it might be a way of doing over drive gearing too boot ) but modern jet engines use that trick a lot so it should work in oil just as good as air. rc-car's is right the TC solenoid does go bad in the 90's-mid 2000's caddy's i got more complaints of it not engaging ( nocking 34 mpg to about 16mpg @ 65MPH~ 1800engine rpm normally to 2500~ and yes it's more wair and tair so it does need tlc or run the risk of Windows 😉 as i have seen someone do that after putting it off for 90+ morning's commute/trips ) then lock-up/failed TC as heavyweight loads ( some people still use big sedans for towing and gardening and i probably will be forced into to doing that with my 2-gen charger as well as my 80's 1-ton K15 truck needs heavy TLC/restoration work or house stuff and my car right now is getting my TLC first 😑) or hot days can make it over heat and fail and id remove the transmission case to replace the TC ect but not to bad % of R&R money wise/reputation and using a better trans cooler and R&R-maintenance at fairly reasonable regular intervals will help and im glad i skipped using the 8-speed automatic as RC-car's was saying its not great and in a hotrod/charger more money and headache from turning the TCM ect. even if there's a kit to do it with a BBM/hemi makes my TR6070 a better choice ( evan if it's more work upfront but rewarding later on ) thanks for warning / reminding me
@@michaelbenardo5695 The 4 speed Dual Coupling Hydramatic will not fit in a 61 - 64 Catalina or Grand Prix. Only the Bonnevilles and Star Chiefs. Reason being the floor hump for the trans is smaller for the Catalina and Grand Prix. I tried it, the big hydramatic hit the floor board and the trans needed another 3 inches before the crossmember could be installed. You would have to change or modify the floor pan.
GM is famous for letting the customer sort their problems out for them, Then they perfect it and the next year they kill it. Same can be said for their Engines!
4T60E was notorious for destroying the reverse reaction drum or "stove pipe" so much that aftermarket companies were offering hardened versions of it. This really was a big problem when mated to the LQ1 3.4L DOHC engine in the GTP and Lumina possibly due to the high torque the engine could deliver at high RPMs. In fact, I remember reading about the development of the LQ1 saying GM initially intended it to deliver 250 HP or something crazy like that but had to scale it back due to transmission reliability issues.
I think it's the same box in Volvo s80s too ..
@@Low760 Volvos use the 4T65E, which isn't that much better when used behind higher revving/higher power engines.
Ah, the 4t60 and the 65, the weak point of the platform I love dearly. I'm trying to build my GTP up for more power and I already know that glass transmission is going to give me some trouble.
@@notsogrand2837Just get a custom built one from Monster Transmission and problem solved.
@@extremedrivr Huh, never heard of them. I was gonna go for a Triple Edge but I'll give Monster a look.
Great video fella, one GM transmission that didn’t make the list and was abysmal was the 4T65EV/GT which set fire to many Volvo XC90s with the I6 engine.
I don't know why I like your videos but you have a real talent with the spoken word. No hype, just communication.
I had a 1980 Malibu with the Metric 200 ? transmission. It was a fleet car. It had the lockup issue which I fixed by unplugging it. When it was time to get a new car, at 50,000 miles, the leasing company asked me when the transmission was replaced. I told them it had not been. The lady said, "you must be mistaken. ALL of these cars have had the transmission replaced." I had a 1979 Malibu before that one and it had a transmission replaced at 35,000 miles. That car was driven by another person before I got it.
Having said that, the Malibu Classic hardtop was a great car otherwise. No power but I live in flat country.
Had a 1980 Buick Century with the 231 V6, THM200 and no lockup. Also a fleet car... lots of highway miles... 62,000 in two years. Transmission survived, barely.
Another very compelling video. Having rebuilt and destroyed a number of GM4L70E transmissions and spent way too much time in the Transtar and Sonnax catalogs, it's a topic near and dear to my heart.
Very educational and enjoyable, Adam! You have definitely created a very watchable channel appealing to many of us who fondly remember daily drivers of the past. Thank you! 👍👍👍
Why remember? Buy and drive a car from 60’s-80’s. Live.
I seem to remember the TV & modulator were standard design for most of GM's autos (powerglide, th350, 400, etc). Only later did they try to simplify with a TV only, which is one reason the TH200 has poor shifts.
Also, owners should be careful if disconnecting the TCC valve as a long term solution. On some models lockup does play a role in cooling. If the TCC is slipping on the highway you could end up cooking the fluid.
Dealing with something like that in my 1981 Bonneville with the 200-4R. The Lock up isnt working because according the the code the vehicle speed sensor is not working so the computer wont lock the torque converter. I'm currently until I can deal with this better driving it in 3rd for the very reason you just mentioned. I dont want to ruin the transmission by overheating it by running it in overdrive.
With any automatic transmission, use of an auxiliary aftermarket transmission cooler will extend the life of the transmission. The cooler it runs, the less fluid degradation there is, even with modern synthetic fluids such as Dexron VI or Mercon V or LV
Some vehicles are equipped with auxiliary coolers from the factory, but installation of a larger capacity aftermarket cooler is just added insurance against premature failure, especially behind a high performance engine or when a vehicle is frequently used for towing or hauling heavy loads.
@@markschommer7407 Pretty sure the 2004r wasn't being equipped in '81, I bet yours is a 3-speed th-200c.
The speed sensor would be on the back of the speedometer, senses rotation of speedo cable. Not a big deal really if it's a th200c, th250c or th350c, these were all 3-speed. The 4-speed (overdrive) WILL overheat if tq converter lockup isn't working.
Lockup occurred above either 35mph, or 45mph in the case of california emissions.
The th-200c is sensitive to tv cable adjustment, make sure it's right else it'l burn the clutches in just a few miles.
The th350 had a kickdown cable, it wasn't a tv cable and misadjustment didn't lead to immediate damage. Th400 had electric kickdown, from a switch on the throttle cable.
@@thisisyourcaptainspeaking2259 On many GM vehicles with a Turbo 400 the switch was actually on a bracket which supported the accelerator pedal
Great chat. I remember driving a 63 Starfire and being disappointed with the upshift to second gear. Also, your comment on the C6 shift is very true. My 428 powered T-Bird would chirp the tires between both upshifts during hard acceleration.
I had a 63 Olds Starfire it was rough shifting , it had super drive , on flat ground it was fast it weighted in at 4200 pounds , my father bought this for me as my first car at 17 , l drove it from 1970 - 75 great car , great memories thanks for your videos 😎👍 Doug
Being an old Pontiac man, I had a 62 and a 63 Catalinas. If you lived in a flat area, it was almost ok. But I lived in a hilly state and they were total crap. When I got a 70 Cat with a measally 350 2 bbl, I could not believe what a night and day difference. It ran circles around the 389's.
Been a mechanic for 25 years really enjoy your videos great information
Thx!
Great presentation again Adam! I don't know what GM was thinking when they began putting the Metric 200 transmissions into larger V8 powered cars. My uncle went through 3 of them in his 81 Caprice coupe back in the day. Even the 82 Trans Am and Camaro had a turbo 200 in it. My high school shop teacher did a transmission swap demo in class on his 82 Trans Am when I was in high school. A Turbo 350 went in it's place. Comparing the size of the output shafts against each other (200 vs 350), it was pretty clear which was the stronger and better choice.
Along with the Rotomatic, Chevrolet's Turboglide (1957-62) was complete disaster.
The 58 - 59 Buick Flight-Pitch DynaFlow, similar to Chevy's TurboGlide but larger, was not the greatest either. It wasn't so much unreliable as it was so slippery that it made the "regular" Dynaflop seem fantastic by comparison. GM, unfortunately, has done some pretty stupid things, things that the haters immediately latched onto.
The 82 trans am and z28 with the crossfire engine-th200 trans was an INTERESTING combo. I know it's fiction but a season 1 episode of knight rider kitt towed a car and broke the alpha circuit in the transmission.
As I recall when the Roto Hydramatic AKA Jetaway Hydramatic was released. I red an article probably in Popular science, or Popular mechanics in the late '60s that GM would not provide repair kits or detailed manuals, as the new transmission was so reliable that in the most unlikely event of a failure that you would have to use a factory rebuilt unit. Seems that it was one of the worst up to that point.
In the late '50s there was the Turbo Powerglide. (I think that is what it was called).
JC Whitney used to sell a conversion kit to install a regular 2 speed Power Glide.
A neighbor teenager had a lawn service so he could save enough to buy every teen age boy's dream in '55 to have a '55 rocket 88 Olds. When it was finally delivered after a long wait it had a Buick Dyna-flop. Did not accept delivery.
Although not GM I think that Packard with their "Ultramatic" had probably the most un reliable transmissions. From what I understand it was a factory philosophy of NIH. Depended on precision bushings with no seal rings, the clutch steels were burnt blue like a hand from an antique watch..
Ford had the 70s C4 Clutches fail just out of warranty at 12k. Then the C5 which would suddenly just stop working. I have no idea what the problem was. It was so bad that my employer, Motorola at the time forbid us from buying a vehicle with a C5.
The jetaway 315 is the last revision of the old hydramatic 4 speed. Dual coupling 4 speed used in Cadillac up to a few units in 64’. The slim Jim is the turd you’re describing. Olds and Pontiac.
I had a 1992 Lumina coupe with the 3T40 and the lockup solenoid got stuck on it. I replaced it myself and it was a surprisingly easy fix! I only paid $400 for the car at the time so I didn't care if it was successful or not. But anyways the 3t40 coupled with the 3.1L MPFI V6 was decent. Good passing power for he most part but man was second gear LONG!
I had a 92 Beretta with a lockup solenoid that started sticking. When I looked at the procedure for repairing it, it seemed like the whole left side of the car would have to come apart! I just unhooked it and drove it like that until it finally went to the scrapyard. I put more than 100,000 miles on that car over 7 years, it really did me right even though it completely fell apart by the end. I never got a Check Engine light and only lost 1 or 2 mpg for disconnecting the solenoid.
“…you enjoy forms of torture!” 😂 YES, I have rebuilt ONE of those roto-messes and NEVER AGAIN! Very torturous indeed! Took me awhile but I’m finally getting around to watching/listening to this & “best transmissions” porch chat vid’s. So glad you mentioned that incredibly well engineered 425 setup. Was a very interesting combination of tech; I own two 1955 Buick Super Riviera’s, both w/“Switch Pitch” or, as was newly called then, “Variable Pitch” Dynaflow! Also had inherited my grandfather’s 1975 GMC Palm Beach Motorhome with 455 Olds front wheel drive trans setup.. loved that motorhome