Hey my 91 firebird with the 700r4 is acting weird. No slipping etc but when im cruising around 35-40 it feels like its shifting from overdrive to drive all the time. Maybe its 3rd to 4th but it does it when im in overdrive and drive, no difference at all. Dont know if its the way these trans are or my cables need adjusted. Never had a car do this before. Thanks everyone!

 

Go to the speed that is creating the problem. Hold steady at that speed. Now touch the brake pedal just enough to make the brake lights come on, and this will unlock the torque converter clutch. You should see the tach jump apx. 200 - 300 rpm. Then let off the pedal and the rpm's should drop back down. If it was a 3-4, 4-3 shift, you should see the tach jump apx. 400 - 600 rpm.

 

Hey thank you! next nice day i will take it out and give it a try! hopefully thats it lol