My '92 400e drivers seat was wracking out of shape when lowering the back edge of the seat bottom. I found the right rear actuator was not moving, and was stuck at the top position. I loosened the seat, tipped it forward and started poking at things. It started working again, couldn't replicate the problem.

Last week my wife told me the seat felt tilted. Checked the rear adjustors, sure enough they were out of synch. I dismantled the gearbox on the right rear, and found that the very end of the receptacle for the flex shaft was stripped out, but only about 1/16". This is the end of the worm gear that drives the adjustor. Looks like the flex shaft is barely engaging the square hole on the end of the gear. I slid the shaft forward until it was about centered in it's travel and put it back together. I assume that it will fail again at some point.

Anyone know where to get seat parts, other than mining a salvage yard?