ok, the usual problem with 1991 740 aw trannys. first, od would shut off during driving. i had to play with it alot to turn od back on, and when it was back on, all was fine. i later had the od switch relay repaired and prb never came back. next stop, after this was fixed, car would begin to only shift into 4th after car got warm. once it got into 4th, trany shifted smooth as ever. so, i had the od relay repaired as well, and still no change. next, i heard that it was a solenoid thing. i took it to get blown into with some compressed air to possibly clean out any gunk in the 90 degree passage inside. put it back on, and still no 4th gear. next, i detached the soleniod vrom the tranny again, but this time, looked into it while i played with the od button on the shifter, and no movement by the solenoid or any noises from it. what do i do next? does it mean the solenoid is bad? or do i have to expect that it is a mechanical thing now inside the tranny? just to indicate, tranny still goes into 4th gear, but only after extensive driving for about an hour id say.