well i took my trans to work today so i could take it apart there, found out what was wrong, the bottom two rings on the oil pumps were the wrong size and a smoked low reverse band. planning to put it back together by end of the week. apparently when the trans was warm the fluid was too thick to get by the miss sized rings, but as it warmed up the fluid escaped past it causing me to loose reverse and third gear(maybe)
Wish I knew something about trannys. That is the one thing I don't do myself. Of course I can change fluid, replace a clutch on a manual, or adjust the bands in a C4. beyond that they are just a lot of cute little throwing rings. Guess I need to learn. Hope that fixes your Problem and you're back on the road this week.
Zoomzoomguy, Be sure to replace the reverse servo piston/seal. It could be the reason the reverse band burned. The seals tend to crack along the rim of the piston where they are bonded.
