Hi, I have a 1985 Pontiac Firebird Trans Am with the stock carbureted 305 and a th700r4 transmission. The transmission has been nothing but problems for me for the last 5 years, every time a put a seal in it leaks somewhere else and is shifting incredibly hard into each gear...

I've been looking at some options to replace it and was wondering if anyone has put a 4l60 in there firebird/Camaro as a replacement. I'm on a tighter budget and trying to find something I can put in myself without having to modify the driveshaft or rear end. I don't have a problem making up a cross member for the car.

Will the 4l60 directly fit into this car?
Can I use a 4l60E without adding electronics?
Should I just find another 700r4?

Any help would be appreciated, not sure how much longer it will stay on the road with the current trans.

 

How many miles on the transmission? which seals are leaking now? The hard shifting may be broken accumulator spring(s)- a quite common problem or Throttle cable badly out of adjustment.
- 4l60 just a name change about 1990-i think pass car trannys through '92 likely will work.
-4L60E will not work
-not a bad idea-depending on what you can find in 2025...
Fixing the tranny in the car now probably easier than locating a suitable replacement and then swapping unknown,possible defective tranny in and trying it.

 

pull the 700 out, get it rebuilt, reinstall it, dont have any more issues.

easy peasy lemon squeezy

 

Transmission only has 134000km on it, seems to slip a little in 4th but only at random and at higher rpms. Perhaps I adjust the TV cable and see about the shifting. My friend told me he has a working Turbo 350 I can buy off him so maybe that's a better route. It's unfortunate that my local scrap yard crushes anything older than 20 years... I'll look into the accumulator spring or rebuilding it. Was quoted $2000 for rebuild (removed from car), kit is $250 but I've never opened an automatic other than to change a filter.

Pump O-Ring / Gasket is currently leaking