need help with 1990 eldo tranny
 

i posted on here a while ago but i cant figure out where. anyways i have a90 eldorado and the transmission is shot and i need to figure out how to fix it on a budget. i have been watching for a salvage yard tranny that either has low miles or has a rebuild, also have a lead on another used one with 12000 miles for 500 bucks. my question is, i have heard that there are different trannys and the plate on the back will tell you which one it is, which part has to match? what happens if i get the wrong one? what if i get the computer with ithe new one, will that fix any issues i may have? how hard is it to rebuild mine? i build high performance small block chevys and i know allot about cars but i have never dug into a tranny. i have been told if i simply follow the charts i should get it right?? i priced a new tranny intown at 990 dollars and thats me doing all the work. thanks!

RE: need help with 1990 eldo tranny
 

found my first post, it explains what happened. i now know it is shot, the stuff in the pan was the clutch disc thingies

https://www.cadillacforum.com/m_2457..._/tm.htm#25954

RE: need help with 1990 eldo tranny
 

Josh,

There were two different transmissions used in the 90 Eldorados, and it was the same way in 90 Sevilles. There was a generic one for the majority of cars, and a special one with a lower 3.33:1 final drive ratio which was used only in 90 1/2 Eldorado Touring Coupes, and 90 Seville Touring Sedans (STS). I don't recall the code, but I think it is a three letter thing starting with K. This will also be found on your car's factory broadcast sheet if available. Chances are the tranny the guy has is the generic one with the higher FDR so you should be fine.

It's interesting that your tranny failed so soon. My 90 STS is at 143,000 and it shifts like brand new (can hardly feel it). My 90 Eldorado Touring Coupe's is at 163,000 and the tranny is bad, but still I can still drive the car. It just shifts really hard from gear to gear and I don't think the VCC is engaging at highway speeds. That will all be fixed by the 5 speed conversion though;)

Steve

RE: need help with 1990 eldo tranny
 

Haha, I have never heard a guy who builds high-po Chevy engines call something "thingys", kind of amusing I think. Hmmmm, if its electronic which I am sure Cadillac stopped putting complete hydraulically controlled in them, you might have a 4L60E or 4L80E? I am not completely sure on that though. If they ever produced a FWD model of your car then it would be 4T60E or 4T80E possibly.

Transmissions can be a pain at times. The electronic models have more parts shoved in them I.E. solenoids-wires-etc. So assuming in your engine builds you calibrate comp ratios, valve lifts, gaps etc doing a transmission will be remotely close to how you build a mill. The main factor is KEEP EVERYTHING CLEAN!!!! - Keep things in ORDER or you willget mixed up also. I have a Factory repair manual for an 1989 Eldo but no 1990. I doubt there is a big difference in the transmission if there is but it should be the same model. If you want me to check something out in my 1989 book let me know.