swapped the trans in a 1988. It had lost all gears but 1st, but didn't really slip or anything, but the only gears I had were 1st and reverse. The scrap yard replacement I bought came with the Torque Converter and needed only to have its tail swapped with the old one to fit. Dropped the pan to install a new screen and filter and didn't notice any unususal junk in it at all, bout a half ounce of powdery stuff around the magnet, talcum powder in consistancy. Car ran fine, shifted fine etc for a month or so then the original problem has seemingly re-appeared. Help! Only additional symptom of note is that it seemingly lost 2 quarts of trans fluid in the 1000 or so miles it was driven. There isn't any fluid in the radiator that I can see, still green and not foamy, and no evidence of any substantial leakage on the ground where it is parked. I wonder if it might not be Computer related or whatever and is there any way to test it with a shadetree guys tools.

 

The 1988 cars did not have computer controlled transmission, except for the torque converter clutch. The oil leak you mentioned will mess the transmission up and allow it to slip. My guess is that the replacement may have been bad, or the TV cable was not adjusted properly, and caused the transmission to go bad, or you are driving the car too hard.