Hi,

I am having a problem with the 1 to 2 shift on a stock 700r4 in a '92 bird. It has been doing this since I bought it a few years ago, so I don't know the history of the vehicle.

Under normal acceleration it shifts very sloppy (not as firm as it should be). At WOT it shifts incredibly early, about 2500 rpm, but it does seem somewhat firm. The 2 to 3 and 3 to 4 shifts are perfect under normal acceleration and under WOT.

I replaced the governor with a known good one, I swapped it with one in my '91 that shifted fine, so I know it's not that. I dropped the pan and changed the filter and fluid. The old fluid looked perfect and didn't smell or look burnt at all.

I haven't hooked a pressure gauge up to it yet, but I am guessing that it will probably show a low pressure shift. I do not know what that would mean as far as what's wrong though. Has anyone ever experienced this type of problem and if so what was the cause?

I am not familiar with the internals of the tranny, is there something in the valve body which might be causing this? or maybe the clutches?

Thanks,

Bill

 

If the 1-2 WOT shift is low and the 2-3 & 3-4 WOT shifts are on time, then I would look at the 1-2 shift valve in the valve body and see if there is a broken or missing spring here. Since you said the 1-2 WOT shift is firm, then the line pressure does not seem to be an issue here.

 

Thanks PRO, this sounds like exactly the advice I was looking for !!!

 

I have a similar question aswell but my trans was rebuilt yrs ago and added a shift kit,vette servo.It worked great and then a few months ago it wouldnt shift out of first no matter what.I had the same tranny shop fix it..they said it was something with the check valve or ball had too much vasoline and wasnt moving in the groves..etc.

I just recently put the trans back in when I did my engine swap and I followed the tech article of adjusting the tv cable but i find 1-2 is very soft and early which bogs the motor down..3-4 isnt nearly as firm as it once was either.If I put the car in first gear only and try to even do a small burnout..it will shift into 2nd at around 3500rpm everytime.Does this make sense to anyone?I think I need the whole thing rebuilt again for it to feel as hard as it was when it was first built.

 

"I had the same tranny shop fix it..they said it was something with the check valve or ball had too much vasoline and wasn't moving in the grooves..etc." This is BS....

The TransGo Performance Shift kit that I offer should fix this. It has the large boost valves, Corvette servo, new accumulator pistons, new accumulator pins, Torlon checkballs, etc.

 

thats what they installed when i first built my trans and it was awesome.but now it feels stock again when all i wanted was the trans to shift out of first lol.not remove the shift kit.

well i have a new trans guy that i know does good work..and he is a local pro racer and when i told him about my trans he said its an easy fix but now would be a good timeto step up a few more upgrades and rebuild it for power and a higher stall converter for my 383.my 2800 is good but a 3200 or a lil more would be a snappy combo.

 

Find out what he wants to do exactly? What does he consider to be upgrades? This will tell us if he is "any good" on 700R4s. There are a lot of "so called" performance transmission builders that cannot build a good 700R4. Get everything in writing as to what he is going to do here, and get back on here and let me know. His "parts list" will tell us a lot....