Pontiac Repair: 1999 Grand Prix, clutch assembly, tranmission

Question
My daughter recently bought the 1999 Grand Prix, It will not shift into overdrive unless going downhill, off the gas, as soon as you touch the gas pedal, the car shifts right back into drive.Any help would be appreciated.

Answer
Hi Dale:

There is not going to be an easy fix to this problem. has any service engine soon lamp come on at all? the gears 1-3 all shift okay??? If they are working okay then it's not an electrical issue to the tranmsission and it's going to be a mechanical issue of some sort inside the tranmission. dos the engine rpm's flair "spike" when it's trying to shift into 4'th gear/ if so that is a sure sign of a mechanical issue with the 4'th gear clutch assembly inside the tranmission. have you checked the fluid level and condition? if the level is low there is a leak and that can casue issues. If the fluid is dark brown or smells burnt that is a sign that the transmission is not healthy and it's going to have to come out of the car and apart. Good luck :0