New to site. Need help with biggie...Driving moderate speed with cloud of smoke out the back. Underside coated with trans fluid. Cleaned up but can't see anything unusual. Fluid low (no suprise) and added about 2 qts, shifts okay (a little firm between 1&2). No more big leaks. What gives...

 

Probably clutches slipping and overheating the fluid so it blows out the overflow. Had that happen on my 90' at about 140k. At that time it was a rebuilt trannie for me.

 

If you pulled up your carpet & ripped up the trans cover, this is what you'd see.



Try to determine if that's where your leak came from. If not, wash it thoroughly with engine degreaser (follow the instructions on the can) & then take a few short test-drives until you get a SMALL leak that you can pinpoint.