@1:32 The Problem with this video is that the Holley bracket 20-121 in the video is not the one you get when you order it. Beware they will send you one that looks like the one in the video except the stud is lower just above the bottom hole and is stamped with a letter H. What this does is increase the stroke so you won't get the correct pressure rise. The one in the video is correct. Holley doesn't even know what they're selling
My 400 comes from a 1 ton truck and I did have to run a vacuum line. Because it is an electric kickdown I also had to install a B&M kickdown to the holly carb as my 80 Trans-am did not come with a 400. With factory 400 trucks flooring the gas closes the circuit which engages the kickdown. On my car WOT closes the circuit engaging kickdown. The video is missing this step.
in a GM Turbo Hydro 350, should the kick down cable be tight when the accelerator is not depressed? Mine has a bit of slack when the accelerator is not depressed or car is off.
TH350 has a TV 'throttle valve' cable & a vacuum modulator & they both need to be hooked up & adjusted properly or premature trans failure is going to occur . It may last a long time adjusted improperly but ultimately the clutches & band will get smoked . They both regulate internal pressure for softer & firmer shifts so trans does not beat its self & you to death and they raise line pressure when more trans gripping/holding power is required as when accelerating or passing. Later ? 1979-1980-1981 TH350's also have a lock up torque converter . The connector is on the USA driver side of the trans & if out & visible the input shaft looks similar to a 700 input shaft. A few parts are interchangeable from a lockup & non lockup . The case, direct drum & pump are different & it has a small axillary valve body . Some TH350's also had a single blade switch by TV cable & this as I recall had something to do with engine timing in the days of early smog emissions . Last year for TH350 I believe was 1981 then the 700 trans was used . TH400 uses a vacuum modulator for basic shifting up and down under normal driving conditions . It utilizes a electric solenoid for the 'ultimate' down shift at WOT throttle positions . Without the wire hooked up you will never achieve maximum RPM the trans is capable of unless you manually down shift . Some early TH400's had 2 blades on the switch connector . One was for the trans kick down and the other was for a Variable Pitch Torque Converter . Yes, a converter with to stall speeds . Its is part of what enabled those old heavy almost 5000 lb cars to literally smoke the rear tires & I know this because I have driven many of them . BTW if you want a performance trans to last then IMO you want one with a good firm shift upon heavy acceleration but not one that snap shifts . A snap shift will literally snap transmission and rear end parts . I hope this answered some questions & helped some of you .
Ultimatehobbyreviews I'm not always online but you can ask & if I know I'll share info. You don't usually have to drop the pan to change the cable & there are different cables so you need to be sure you get the right one which is sometimes hard if someones worked on it before using the wrong parts . If you disconnect the cable up top there's usually enough slack to unhook the wire link on the bottom . Some use a top hat type seal & some just a O ring in the groove & some of the bolts are metric & some not . Just use a little slippery something 'oil , grease , petroleum jelly ' to re-install the cable end seal . If installed correctly the seals seal without any type added sealer . Also the vacuum modulators 'usually the red stripe ones' are adjustable with a vary small screw driver . Turn it in & it shifts harder and later turn it out softer & sooner & they need ported vacuum not hooked to the carb . When adjusting a Mod I usually do 1.5 turns at a time . Also remember Th350 are all very old so be careful with the modulator bolt because I've seen the mount broken off on some . Good news a bracket is used for a fix & heres one on Ebay that you can look at just in case . eBay item number: 181593727116 I am an avid Ebay user & always looking for a deal & here is a super deal that I strongly racommend & use them myself which is a ATSG manual . I probably have 20 different ones that I refer to . eBay item number: 331317021520
If it's a TH350 without any torque converter lockup modules, like I have, you DO NOT need to run a kickdown cable. I've been slamming my TH350 in my Trans Am around for 7 years without this cable. And so have most guys in the hot rod community that run TH350 trans. There is both a vacuum modulator AND the cable on a TH350, The kickdown only effects the kickdown of the trans from 3rd to 2nd when needed. The Vac modulator is what keeps pressures in the right spot on a 350. As long as you don't mind shifting manually, it will be more than okay.
NickoliKalashnikov47 Actually, you are incorrect ! While your trans will or may last for a while it was designed with the cable and its use is required to work properly . So. What you have is a trans that can not possibly work properly. & A 350 properly set up does not need to be shifted manually.
Actually my trans works perfectly fine! It shifts up and down on its own exactly the way it's supposed to. I'm not going to start an argument about this. The Electronic torque converter lockup 350's NEED a kickdown cable. Non-electronic 350's do not, IF you bulid them correctly
NickoliKalashnikov47 Good for you. I'm happy that you believe that your trans works properly. But just about any trans can be altered from its OEM design so it can/needs to be shifted manually or do other things it was not ever originally intended to do. And sometimes contrary to popular belief that is not always good. And you didn't state that or if your trans had been altered you said ' all ' 350's except LU's don't need a cable. But what you are suggesting/telling people by claiming a/all 350's do not require a TV cable is still incorrect and will more than likely lead to a premature failure. Its just a plain fact that a th350 by OEM design needs a detent cable and only a transmission-ally challenged person would claim otherwise. As for you slamming your trans . Not a good idea. Because the Th350 although they are a very good trans when built properly are inherently weak and should not be slammed or altered to slam. A good firm shift is more than adequate to spin tires & sink you into the seat . A slam does nothing but break things. Anyone that knows anything about a auto trans knows they should not be slammed because that is nothing but a ' shock load ' way beyond the trans capacity and it will ultimately result in its failure. They, 350's are limited by the size of their components which are small compared to a TH400 or 4l80e and I have seen shafts with multiple cracks and twisted completely off & planet gears destroyed along with smoked band & drums. No matter what trans you have it ' must ' be 'dialed into the vehicle' it is in to work properly taking into consideration camshaft, gear ratio, converter stall , weight of vehicle & general use ETC. BTW if a cable was really unnecessary can you imagine the multiple millions of $$$$ GM could have saved by eliminating them ? There is also a TH250 & TH375 but that's another subject.
I have a th400 in my 442 and it doesn't have an electric kickdown for the carb. It has the vacuum thingy connected to the intake. It runs fine like this. Is it supposed to? Am I unknowingly jacking up my transmission? I can't seem to get a straight answer on this. Half of people say it's fine, the other half say I need an electric kickdown...
This video should be called HOW TO INSTALL KICKDOWN BRAKETS AND INSTALLATION OF CABLES ! It does not show how to properly set the cable for engagement!
switched my 2 to 4 barrel holley. now the tv cable is too short. have no idea what trans I have. 70 Impala. I thought I was just going to swap and go. That's a negatory
Can some one help Got a 92 Silverado with 700r4 Problem is that it kicks to 3ed (in both overdrive and drive) and then nun it start going high rpm and it like free spins or something no noise or anything just free spins Hoping I dont need a 3 -4 kit Can drive in 2ed gear Looking around and people saying it could be this Just seeing if some one else has had this problem as well Tips and pointers
This Video is NOT correct because they have the TH 350 and the TH 400 backwards. The TH 350 only requires a Vacuum hook up where as the TH 400 requires the Kick Down cable to the Carb. I have both the TH 350 and the TH 400 in separate cars.
!? Th350 400 are the same 400 holds more torque shaft is lil shorter .and vaccum advance is for shift firmness the cable is for down shift passing both are on these trans. Unless you have newer or added the computer module like The 700r is electronicly contrlled
The video is correct. The kickdown for the th400 is operated via a push button switch located on the gas pedal assembly. I have two th400 4x4 and had a th350.
please remove TH400 from this misleading title, you do not show how to wire / install the kick down switch for it, there is not cable or bracket for it
This video isn't completely correct... I have the gm th400 and it also has a kickdown cable that attaches to an electric switch that I mount to the tranny pan.. Furthermore, it has a single electric switch threaded into the side of the tranny housing... MY QUESTION: I have the th400 with single wire electric switch... I read the switch needs a 12volt 5am source.. Can this be an accessory wire or does it have to be an ignition source? ANYONE?
OK 7 months later . It only needs power when you want it to down shift during WOT wide open throttle . You need a switch which only powers it at WOT & it does not really matter if its controlled by the ignition switch or not but IMO its better if it comes off the switch & fused .
Video is great in showing the different tranys and the cable hookups , BUT, it does not show the setting at all, it states that you should take it to a shop ! You need to retitle your vid !
Here is how to adjust the Transmission kickdown, Take it to shop and have them do it? What the hell? Do you think people waste their time watching these video's so they can take it to a shop? No, because some people want to learn the proper procedure to do it.
hmmmmm this was not how to set kickdown....you put kickdown in position in the bracket and attatched to arm that other detent attaches to then you pull the metal or plastic tab straight up, then while truck shut off, have other person full throttle gas pedal to floor and hold while you then put metal/plastic back down then have person let up on pedal and that will adjust your cable to right fit!! I have been doing alot of upgrades/upkeep on my 80 chevy k5 after my recent engine swap!! which was HELL!!! lol
to prevent trans failure take it to the local transmission shop that makes their living off of trans failures, and have them adjust it. sure ok. just like doctors who are supposed to cure disease and dentists who want healthy teeth.
hey Holley, thanks for not answering any of these questions. Great service.
I missed the part showing the setting of the Kickdown on the TH-350.
This video covered everything but that
My th400 uses a vacuum modulator AND an electronic kickdown.
ALL TH400's use electric KD ! Every one !
@1:32 The Problem with this video is that the Holley bracket 20-121 in the video is not the one you get when you order it. Beware they will send you one that looks like the one in the video except the stud is lower just above the bottom hole and is stamped with a letter H. What this does is increase the stroke so you won't get the correct pressure rise. The one in the video is correct. Holley doesn't even know what they're selling
My 400 comes from a 1 ton truck and I did have to run a vacuum line.
Because it is an electric kickdown I also had to install a B&M kickdown to the holly carb
as my 80 Trans-am did not come with a 400.
With factory 400 trucks flooring the gas closes the circuit which engages the kickdown.
On my car WOT closes the circuit engaging kickdown.
The video is missing this step.
So all three cables need to be hooked up? The throttle cable, tv cable, kickdown cable?
in a GM Turbo Hydro 350, should the kick down cable be tight when the accelerator is not depressed? Mine has a bit of slack when the accelerator is not depressed or car is off.
TH350 has a TV 'throttle valve' cable & a vacuum modulator & they both need to be hooked up & adjusted properly or premature trans failure is going to occur .
It may last a long time adjusted improperly but ultimately the clutches & band will get smoked .
They both regulate internal pressure for softer & firmer shifts so trans does not beat its self & you to death and they raise line pressure when more trans gripping/holding power is required as when accelerating or passing.
Later ? 1979-1980-1981 TH350's also have a lock up torque converter .
The connector is on the USA driver side of the trans & if out & visible the input shaft looks similar to a 700 input shaft.
A few parts are interchangeable from a lockup & non lockup .
The case, direct drum & pump are different & it has a small axillary valve body .
Some TH350's also had a single blade switch by TV cable & this as I recall had something to do with engine timing in the days of early smog emissions .
Last year for TH350 I believe was 1981 then the 700 trans was used .
TH400 uses a vacuum modulator for basic shifting up and down under normal driving conditions .
It utilizes a electric solenoid for the 'ultimate' down shift at WOT throttle positions .
Without the wire hooked up you will never achieve maximum RPM the trans is capable of unless you manually down shift .
Some early TH400's had 2 blades on the switch connector .
One was for the trans kick down and the other was for a Variable Pitch Torque Converter .
Yes, a converter with to stall speeds .
Its is part of what enabled those old heavy almost 5000 lb cars to literally smoke the rear tires & I know this because I have driven many of them .
BTW if you want a performance trans to last then IMO you want one with a good firm shift upon heavy acceleration but not one that snap shifts .
A snap shift will literally snap transmission and rear end parts .
I hope this answered some questions & helped some of you .
Ultimatehobbyreviews
I'm not always online but you can ask & if I know I'll share info.
You don't usually have to drop the pan to change the cable & there are different cables so you need to be sure you get the right one which is sometimes hard if someones worked on it before using the wrong parts .
If you disconnect the cable up top there's usually enough slack to unhook the wire link on the bottom .
Some use a top hat type seal & some just a O ring in the groove & some of the bolts are metric & some not .
Just use a little slippery something 'oil , grease , petroleum jelly ' to re-install the cable end seal .
If installed correctly the seals seal without any type added sealer .
Also the vacuum modulators 'usually the red stripe ones' are adjustable with a vary small screw driver .
Turn it in & it shifts harder and later turn it out softer & sooner & they need ported vacuum not hooked to the carb .
When adjusting a Mod I usually do 1.5 turns at a time .
Also remember Th350 are all very old so be careful with the modulator bolt because I've seen the mount broken off on some .
Good news a bracket is used for a fix & heres one on Ebay that you can look at just in case .
eBay item number:
181593727116
I am an avid Ebay user & always looking for a deal & here is a super deal that I strongly racommend & use them myself which is a ATSG manual .
I probably have 20 different ones that I refer to .
eBay item number:
331317021520
If it's a TH350 without any torque converter lockup modules, like I have, you DO NOT need to run a kickdown cable. I've been slamming my TH350 in my Trans Am around for 7 years without this cable. And so have most guys in the hot rod community that run TH350 trans. There is both a vacuum modulator AND the cable on a TH350, The kickdown only effects the kickdown of the trans from 3rd to 2nd when needed. The Vac modulator is what keeps pressures in the right spot on a 350. As long as you don't mind shifting manually, it will be more than okay.
NickoliKalashnikov47
Actually, you are incorrect !
While your trans will or may last for a while it was designed with the cable and its use is required to work properly .
So.
What you have is a trans that can not possibly work properly.
& A 350 properly set up does not need to be shifted manually.
Actually my trans works perfectly fine! It shifts up and down on its own exactly the way it's supposed to. I'm not going to start an argument about this. The Electronic torque converter lockup 350's NEED a kickdown cable. Non-electronic 350's do not, IF you bulid them correctly
NickoliKalashnikov47
Good for you.
I'm happy that you believe that your trans works properly.
But just about any trans can be altered from its OEM design so it can/needs to be shifted manually or do other things it was not ever originally intended to do.
And sometimes contrary to popular belief that is not always good.
And you didn't state that or if your trans had been altered you said ' all ' 350's except LU's don't need a cable.
But what you are suggesting/telling people by claiming a/all 350's do not require a TV cable is still incorrect and will more than likely lead to a premature failure.
Its just a plain fact that a th350 by OEM design needs a detent cable and only a transmission-ally challenged person would claim otherwise.
As for you slamming your trans .
Not a good idea.
Because the Th350 although they are a very good trans when built properly are inherently weak and should not be slammed or altered to slam.
A good firm shift is more than adequate to spin tires & sink you into the seat .
A slam does nothing but break things.
Anyone that knows anything about a auto trans knows they should not be slammed because that is nothing but a ' shock load ' way beyond the trans capacity and it will ultimately result in its failure.
They, 350's are limited by the size of their components which are small compared to a TH400 or 4l80e and I have seen shafts with multiple cracks and twisted completely off & planet gears destroyed along with smoked band & drums.
No matter what trans you have it ' must ' be 'dialed into the vehicle' it is in to work properly taking into consideration camshaft, gear ratio, converter stall , weight of vehicle & general use ETC.
BTW if a cable was really unnecessary can you imagine the multiple millions of $$$$ GM could have saved by eliminating them ?
There is also a TH250 & TH375 but that's another subject.
You showed how to hook the cable up but in no way showed how to set up the cable !
Will the bracket for the turbo 350 work with a stock intake and a demon carb?
Ok I have a th350 and it has cable and vacuum
So does my th350
I have The Kick Down switch hooked to radio power so that it is only on where the switch is on.
i thought you hooked it up to the flux capasitor
I have a th400 in my 442 and it doesn't have an electric kickdown for the carb. It has the vacuum thingy connected to the intake. It runs fine like this. Is it supposed to? Am I unknowingly jacking up my transmission? I can't seem to get a straight answer on this. Half of people say it's fine, the other half say I need an electric kickdown...
This video should be called HOW TO INSTALL KICKDOWN BRAKETS AND INSTALLATION OF CABLES ! It does not show how to properly set the cable for engagement!
OneBad88S10 Let a trans mechanic set up the TV cable.
if you mess it up, ur 700r4 will be burned up in 100 miles.
switched my 2 to 4 barrel holley. now the tv cable is too short. have no idea what trans I have. 70 Impala. I thought I was just going to swap and go. That's a negatory
ZCan you do this video for a '60s Powerglide?
There is no cable on a Power glide, only vacuum line from trans.
You went through all that S**** just to tell us to have someone else do it. GEE THANKS
Th400 uses that kickdown cable as well. Or at least mine does.
I wish folks would make sure that the voice will come through before posting any video
why this guy using rubber gloves if the motor is cleaner than crap?.
Can some one help
Got a 92 Silverado with 700r4
Problem is that it kicks to 3ed (in both overdrive and drive) and then nun it start going high rpm and it like free spins or something no noise or anything just free spins
Hoping I dont need a 3 -4 kit
Can drive in 2ed gear
Looking around and people saying it could be this
Just seeing if some one else has had this problem as well
Tips and pointers
I have this same problem but on a turbo 400
This Video is NOT correct because they have the TH 350 and the TH 400 backwards. The TH 350 only requires a Vacuum hook up where as the TH 400 requires the Kick Down cable to the Carb. I have both the TH 350 and the TH 400 in separate cars.
!? Th350 400 are the same 400 holds more torque shaft is lil shorter .and vaccum advance is for shift firmness the cable is for down shift passing both are on these trans. Unless you have newer or added the computer module like The 700r is electronicly contrlled
The video is correct. The kickdown for the th400 is operated via a push button switch located on the gas pedal assembly. I have two th400 4x4 and had a th350.
My th350 in my 79c10 has both the tv cable and a vacuum valve pulling from absolute full vaccum on intake down to valve.
please remove TH400 from this misleading title, you do not show how to wire / install the kick down switch for it, there is not cable or bracket for it
It is electric an vacume modulator
This video isn't completely correct...
I have the gm th400 and it also has a kickdown cable that attaches to an electric switch that I mount to the tranny pan.. Furthermore, it has a single electric switch threaded into the side of the tranny housing...
MY QUESTION:
I have the th400 with single wire electric switch... I read the switch needs a 12volt 5am source.. Can this be an accessory wire or does it have to be an ignition source? ANYONE?
OK 7 months later .
It only needs power when you want it to down shift during WOT wide open throttle .
You need a switch which only powers it at WOT & it does not really matter if its controlled by the ignition switch or not but IMO its better if it comes off the switch & fused .
click bait crooks never tell you what you need to know.
Video is great in showing the different tranys and the cable hookups , BUT, it does not show the setting at all, it states that you should take it to a shop ! You need to retitle your vid !
Th 400 is electric an vacume modulator both
Gm 400 transmission kickdowm
Here is how to adjust the Transmission kickdown, Take it to shop and have them do it? What the hell? Do you think people waste their time watching these video's so they can take it to a shop? No, because some people want to learn the proper procedure to do it.
On god
whats your basis?
hmmmmm this was not how to set kickdown....you put kickdown in position in the bracket and attatched to arm that other detent attaches to then you pull the metal or plastic tab straight up, then while truck shut off, have other person full throttle gas pedal to floor and hold while you then put metal/plastic back down then have person let up on pedal and that will adjust your cable to right fit!! I have been doing alot of upgrades/upkeep on my 80 chevy k5 after my recent engine swap!! which was HELL!!! lol
isuzu trooper 3.1 TV CABLE ADJUSTMENT
to prevent trans failure take it to the local transmission shop that makes their living off of trans failures, and have them adjust it. sure ok. just like doctors who are supposed to cure disease and dentists who want healthy teeth.
You never actually said how to adjust the TH350. 🤦♂️
That didn't help at all
This video does not show to to SET the kickdown. This video is just how to install the cable! WTF
.....never showed how to adjust either.
Well that was a complete waste of everyons time.
No help.didnt even show how to set it.come on holley!