B&M Shift Point Change Kit For TH350, TH400, 700R4 or 4L60 Automatic Transmissions & Road Test
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- Опубліковано 21 жов 2024
- DIY video for changing shift points on GM automatic transmissions. If you have made any mods, like bigger cam, better flowing heads, etc, to your engine you may need to raise your shift points to take advantage of them.
I just did mine, factory weights were 16 grams each, shifted around 2000 driving easy and 4000 at wide open throttle. I changed both to weights that were 12.3 grams each, raised easy driving to 2500 and wide open to 5200 or so. Also softer springs will give you a snappier shift, stiffer springs will give softer shifts.
Aren't you required by law, that when you pop open the governor cap, you say "Hello Guvnar" in a heavy Cackney accent?
I just had my auto built to performance specs for my Buick powered commodore and also had a 2200 convertor (stock was 1600). Also fitted long tune headers, free flowing sports system, some intake mods and loaded my dyno tune cal. The auto shifts between 3500-4000 and won't rev over 4000 until about 200km/h+ Stock it would shift at 4500 and hold 3rd till top speed, but now it's 4th before 100km/h at WOT. I suspect they auto builder changed the governor to suit a potential turbo install years down the track and lowered the shift points rather than for the current setup, I mentioned I wanted the strength for a turbo later but to suit the current engine. Since I am an auto n00b as I have not driven an auto for over a decade and know not much about them I am hoping this is the solution.
I need to change the weights/springs until I get a 5500 peak rpm which ever gear happens to be the highest shift point. Raising the part throttle shifts will be great too, I like about 2500-3500 at about 25% throttle. In manual mode the auto/converter combo is great, much quicker than before and the shifts are very fast and firm, not that lazy clutch burning shifts before. Just the auto mode points are poor.
@50105nelson ...if you have a vacuum modulator on your transmission you can get a adjustable modulator from summit racing, that may help you out.
Also make sure your kick down cable or TV cable is adjusted properly.
Changing the weights always seems to raise both part throttle and full throttle shift points.
Thanks a TON for taking the time and effort to make this video !! AWESOME !!
@HotRodStart ....thanks for the comments, if you have not found the info yet the way you adjust the kickdown cable for a th350 is there is a plastic tab you need to lift up with a screwdriver, it is near the bracket that holds the cable then have someone push the gas paedal to the floor from inside the car, while they hold the pedal down you then push the tab back down to lock the adjustment.
Changing your rear end gears will not change the shift points, Yes I did just change one weight, I would recommend just changing one weight at a time it makes it much easier. In my experience it has always been a guessing game changing the weights. You never really know how much it will change.
I had a 94 Z28 a while back that had the factory performance package in addition to being a Z28, it came with 3.42 gears z rated tires and no speed limiter, it shifted at 6000rpm. What rpm r u getting.
You may have some bad seals inside the transmission or clutches. You could try a product called AT205 Re-Seal, it will soften the seals and may get some more life out of your tranmission without having to rebuild it. Also change the fluid if you have not already.
Great video very detailed and informative. Be blessed
Good kit, I use it all the fucking time, change my fucking shift points on my fucking car, works fucking awesome
Have you done any other work to the trans or is it all stock? Stock valve body?
I saw the Governor has TWO weights one on each side. Did you change both sides to 11 gram weight or just one side?
Changing one weight will change both shift points. Sometimes the 1-2 shift will raise more than the 2-3 but they both will change just by changing one weight
Quick question for you, because you obviously know your stuff. My dad had a stock 74 z28 Camaro with an M40 transmission. He told me that if you manually shifted the car into 1st gear, stood on the brakes and revved it out, you could launch the car and the transmission would shift through all the gears with the shift lever still all the way back in first. He said if you were up to speed and didn't move the lever into drive, as soon as you slowed down and it would start downshifting , it would drop right into first and just about put you through the windshield when it downshifted. I can't find any info on this online, but it's sounds pretty damn cool like GM had a built in launch feature in the M40 without advertising it. From what my dad said, only old school M40 fans know about this "feature". Have you ever heard of this? If you do, would you mind filling me in on how this actually works?
With my 373 gear plus tall tires, I need these adjustments for my 700r4 stage 3 trans shifting wayyy too early.
this was an excellent presentations thank you, you mention changing the full throttle shift points but what about part throttle, in my case I want a bigger space between the 1-2 shift and the 2-3 shift, right now they seem to happen real quick and back to back
You need an adjustable vacuum modulator for part throttle adjustments. They're about $15 on Jegs.
@@NateLarsonTheNetNinja 700R4 doesn't have a vacuum modulator. TH350 and 400 do.
Very helpful. Thank you!
Thank you so much. You have one hater but I'm congratulating your video because I was not happy with the way my shift points are.
I need to bump up my shift points after my can install. Few questions... Would changing my rear gears from 2.73s to 3.43s change my shift points? Did you only change one weight? I was under the impression that there is a weight for each shift point? How do you know how much each weight changes it? So then I don't go over my desired limit? Thanks! Car is a 93 Z28 has an LT1 and 700r4.
Does anyone know how to, or if you can get your 1-2 and 2-3 shift points close to equal with the governor? Mine are 1-2 5600 rpm and 2-3 4200 rpm. I would like to raise just the 2-3 to 5500 rpm and leave the 1-2 alone.
Great video you helped me a ton thank you
That is interesting, maybe changing the other weight will help.
I haven't tried the 3.42s yet (still away for winter). It has been shifting around 4600 wot.
THANKS MAN!!!! Very detailed
Is there a way to raise the full throttle shift point without raising the part throttle shift points? I raised both of mine and need to lower the part throttle shifts? Any help?
why the hell would you put a 305 in that.....wow
Another question, I changed out on weight, it made my 2nd-3rd shift exactly where I want it, do I need to change the other weight to change my 1st-2nd shift point?
Thanks for the video. My th350 is shifting from 1-2 and then 2-3 almost immediately. I'd say by the time i'm doing 10 or 15mph, I'm already in 3rd. I have a 454 hooked up to it in a 57 Bel Air with stock rear end gears. Fluid level is good, vacuum is 50 inches at the rear modulator on the trans, TV cable is hooked up with no slack so that as soon as throttle is opened, the TV cable begins to pull out. Any ideas where I might start? Thanks!
Daryl Zihyer how did you get 50 inches of vacuum. thm350 doesn't have a tv cable it has a kickdown with a slot that doesn't start pulling till half throttle or so.
johnapaterson Registering 50" vacuum at the line coming from the intake going to the modulator. Iow, 50" of intake vacuum being delivered to the trans modulator.
Daryl Zihyer My gauge only goes to 30" of vacuum. 50 is quite high and should be around 20 with a stock or close to stock engine. When you pull the vac line from trans end does the rpm raise on engine? Any trans fluid in vac line at modulator? What you have is called stacked shifting- google it. I would look at the kickdown cable again aswell. it should start pulling cable at half throttle or so.
Daryl Zihyer d
Great video!!!
I wanna do this to my 2004r
@HapFletcher ...just the one
My 1-2 didn't so much at all. The 2-3 made the most improvement.
That kit is 75 bucks everywhere I check what a rip off for a few weights and springs.
Damn good video
piss poor lighting