Lately my car cycles gears up and down many times before going into overdrive(4th/lockup?). Looks like it upshifts and then decides that the load is too much, downshifts, again upshifts and so on between 40mph and
50mph even with constant accelerator and level road. There is some associated shuddering.
Transmission fluid and filter was changed 10K miles ago.
I was thinking that there may be something that may be adjustable to make the upshifts happen later. Anybody know how it can be done?
FYI Shifts to 2nd at 10mph Shifts to 3rd at 20mph
-Sume
1993 Grand Am v6 3 speed Automatic transmission
121000 miles