89 T/A, 700R4 won't shift till 2500 when cold
#1
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Car: 89' T/A, 00' Firehawk
Engine: 406 Roller
Transmission: TH700R4 w/2800 stall
Axle/Gears: 3.23 Posi
89 T/A, 700R4 won't shift till 2500 when cold
I've had this issue for years. I normally only drive the car in the summer so I've just dealt with it. When I first drive the car in the morning or after sitting for an extended period of time, it won't shift till it gets to about 2500rpm. When it does shift it shifts freakin hard. It's like that in every gear.
What I have found out is, if i shut the car off, smack the gas to the floor real quick then start it back up the problem goes away.
I'm thinking it has to be something in the TV system because that's the only thing attached to the carb.
I've ran some seafoam trans tune through it, changed the fluid, didn't make any difference. Fluid is full and bright red(before I changed it)
Any ideas would be appreciated.
Thanks.
What I have found out is, if i shut the car off, smack the gas to the floor real quick then start it back up the problem goes away.
I'm thinking it has to be something in the TV system because that's the only thing attached to the carb.
I've ran some seafoam trans tune through it, changed the fluid, didn't make any difference. Fluid is full and bright red(before I changed it)
Any ideas would be appreciated.
Thanks.
#2
Member
Re: 89 T/A, 700R4 won't shift till 2500 when cold
I've had this issue for years. I normally only drive the car in the summer so I've just dealt with it. When I first drive the car in the morning or after sitting for an extended period of time, it won't shift till it gets to about 2500rpm. When it does shift it shifts freakin hard. It's like that in every gear.
What I have found out is, if i shut the car off, smack the gas to the floor real quick then start it back up the problem goes away.
I'm thinking it has to be something in the TV system because that's the only thing attached to the carb.
I've ran some seafoam trans tune through it, changed the fluid, didn't make any difference. Fluid is full and bright red(before I changed it)
Any ideas would be appreciated.
Thanks.
What I have found out is, if i shut the car off, smack the gas to the floor real quick then start it back up the problem goes away.
I'm thinking it has to be something in the TV system because that's the only thing attached to the carb.
I've ran some seafoam trans tune through it, changed the fluid, didn't make any difference. Fluid is full and bright red(before I changed it)
Any ideas would be appreciated.
Thanks.
#3
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Car: 1986 Pontiac Firebird
Engine: 2.8l v6
Transmission: 700R4 transmission
Axle/Gears: All stock 86 year model
Re: 89 T/A, 700R4 won't shift till 2500 when cold
I've had this issue for years. I normally only drive the car in the summer so I've just dealt with it. When I first drive the car in the morning or after sitting for an extended period of time, it won't shift till it gets to about 2500rpm. When it does shift it shifts freakin hard. It's like that in every gear.
What I have found out is, if i shut the car off, smack the gas to the floor real quick then start it back up the problem goes away.
I'm thinking it has to be something in the TV system because that's the only thing attached to the carb.
I've ran some seafoam trans tune through it, changed the fluid, didn't make any difference. Fluid is full and bright red(before I changed it)
Any ideas would be appreciated.
Thanks.
What I have found out is, if i shut the car off, smack the gas to the floor real quick then start it back up the problem goes away.
I'm thinking it has to be something in the TV system because that's the only thing attached to the carb.
I've ran some seafoam trans tune through it, changed the fluid, didn't make any difference. Fluid is full and bright red(before I changed it)
Any ideas would be appreciated.
Thanks.
Last edited by K.i.t.t; 02-10-2023 at 09:33 PM.
#4
Re: 89 T/A, 700R4 won't shift till 2500 when cold
I would say your seals are (becoming) old and brittle. Therefore they don't seal/leak till you build more pressure at higher RPMs. Once oil warms up it softens the seal and they regain their sealing capacity till they cool off again.
#5
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Car: Resto-Mod 1987 IROC-Z Clone
Engine: Alky fed L92 Vortec Twin-Turbo 6.8L
Transmission: My own built/ design 4L80M
Axle/Gears: Custom 12 bolt (4.10:1)
Re: 89 T/A, 700R4 won't shift till 2500 when cold
Excessive TV Pressure can cause late and hard shifts (especially cold, the line pressure will be higher).
Start with looking at the TV Cable (too tight), then the Valve-body.
Start with looking at the TV Cable (too tight), then the Valve-body.
#7
Member
Re: 89 T/A, 700R4 won't shift till 2500 when cold
In th350 transmission cold shift problem can be cause late shifting when fluid is cold. I can only guess that the same could apply to the 700-4R.
I do agree vorteciroc as I had the same situation that he commented on. My TV cable was also misadjusted & caused 2-3 **** problem. Readjuted it & all was well.
I do agree vorteciroc as I had the same situation that he commented on. My TV cable was also misadjusted & caused 2-3 **** problem. Readjuted it & all was well.
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#8
Member
Re: 89 T/A, 700R4 won't shift till 2500 when cold
I remember adjusting that throttle cable long time ago maybe 10 yrs, and don't remember how I did it. I was messing with the distributor cap to set the timing, and then I remember adjusting that cable, and I did it one direction either tighten or loosen, then test drove it and could see I didnt like, then did the other way, until I thought I found the sweet spot. Then I sorta vowed to not ever touch it again.. But now from comments above looks like I'll need to get the handbook out and see how it is supposed to be properly set. Thanks for the direction, was checking my old emails and just saw I got a response! Thanks @vorteciroc
#9
Member
Re: 89 T/A, 700R4 won't shift till 2500 when cold
I should stay on topic with the tranmission shift issue, but just want to say my 89TA had another problem show up and we had to install a new fuel pump to fix it, so I guess that is partially why it's a month later and just sorta now looking at the transmission shift issue again. I have another problem (gee whiz), I need to start another thread for, its for the temp gauge stopped working. Anyways this is my partial excuse for not seeing this till a month later. It's my dad and I working on the car, and most of the mechanical expertise is with him and not me so much. But this forum has saved my car in the long time ago in the past. He visits me usually at least once a month, and usually its then we try to fix something on it.
Link to Fuel Pump Thread: https://www.thirdgen.org/forums/tech...pump-89-a.html
Link to Temperature Guage Thread: https://www.thirdgen.org/forums/elec...ml#post6496243
Link to Fuel Pump Thread: https://www.thirdgen.org/forums/tech...pump-89-a.html
Link to Temperature Guage Thread: https://www.thirdgen.org/forums/elec...ml#post6496243
Last edited by 89GTASC; 03-21-2023 at 08:58 AM.
#10
Member
Re: 89 T/A, 700R4 won't shift till 2500 when cold
I should stay on topic with the tranmission shift issue, but just want to say my 89TA had another problem show up and we had to install a new fuel pump to fix it, so I guess that is partially why it's a month later and just sorta now looking at the transmission shift issue again. I have another problem (gee whiz), I need to start another thread for, its for the temp gauge stopped working. Anyways this is my partial excuse for not seeing this till a month later. It's my dad and I working on the car, and most of the mechanical expertise is with him and not me so much. But this forum has saved my car in the long time ago in the past. He visits me usually at least once a month, and usually its then we try to fix something on it.
Link to Fuel Pump Thread: https://www.thirdgen.org/forums/tech...pump-89-a.html
Link to Temperature Guage Thread: https://www.thirdgen.org/forums/elec...ml#post6496243
Link to Fuel Pump Thread: https://www.thirdgen.org/forums/tech...pump-89-a.html
Link to Temperature Guage Thread: https://www.thirdgen.org/forums/elec...ml#post6496243
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#11
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Join Date: Jul 2006
Location: 212 is up in this Bit@#
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Car: Resto-Mod 1987 IROC-Z Clone
Engine: Alky fed L92 Vortec Twin-Turbo 6.8L
Transmission: My own built/ design 4L80M
Axle/Gears: Custom 12 bolt (4.10:1)
Re: 89 T/A, 700R4 won't shift till 2500 when cold
Well at least that was not a surprise.
Glad to hear it worked out!
Glad to hear it worked out!
#12
Member
Re: 89 T/A, 700R4 won't shift till 2500 when cold
89GTASC;
I will keep note of your solution in mind eventhough my "84 T/A has not had the issue.
I will keep note of your solution in mind eventhough my "84 T/A has not had the issue.
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