LilJayV10

iTrader: (5)

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.

89GTASC

I am having a similar issue but little worse, when its cold it shifts from 1-2 at near 4000 rpms, and then after awhile of driving it'll start to shift earlier. Yeah I guess I let the car sit too much without driving mine. Sad to see nobody responded to you on this thread. But I've been searching on "not shifting" and does seem like a common problem. I think this is the 5th or 6th thread I have seen. I am guessing my issue will get better in the summer when things get warmer. I'm trying to drive mine more often to see if it helps. I noticed if you can give it alot of throttle it'll shift better than if you try to baby it.

K.i.t.t

Sounds like your transmission may be low on transmission fluid, or the transmission filter may be dirty, or possibly the torque converter is worn in an extreme case. I wouldn't know for sure unless i was there in person. Another thing to check is your cable, make sure it's set correctly, they do get stretched & worn out over time. Also check the governor on the side of the transmission, it could be faulty.

Camaro71

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.

vorteciroc

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.

Pro Built Automatics

I agree with vorteciroc here on this one.

72buickgs

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.

89GTASC

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

89GTASC

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

89GTASC

We found our problem and it not shifting until late around 4000 rpms.. It ended up being the transmission throttle valve. And ended up having a transmission shop fix the issue. The throttle valve was stuck. There is a spring mechanism and maybe something else that is supposed to push the throttle valve out when you let off the gas pedal, and it was not being pushed back out all the way. After 9 months of not having 4th gear and it shifting late, the issue finally seems resolved as it shifted driving it easy at less than 2000 rpms. I might start a thread to share this and ask about a TC lockup issue I think mine is still having, but atm I am all kinda of happy to have 4th gear back and it shifting "normal".

vorteciroc

Well at least that was not a surprise.

Glad to hear it worked out!

72buickgs

89GTASC;
I will keep note of your solution in mind eventhough my "84 T/A has not had the issue.