Originally Posted by
Mark Kovalsky
Yes you could. If the trans is overfilled, though I don't think a half quart over would do it it, the rotating parts will whip the fluid into a foam, and that also causes quite a bit of heat. Foamed fluid does not transmit pressure well, so this could also have made the torque converter clutch slip, which would create A LOT more heat.
Mark, could you comment on whether it would have been better if Dan had run a half-quart low rather than a half-quart over with the 4R100 tranny in particular and automatics in general. I've always, if I had to, run the tranny a little low rather than too full.