Hello, problem is intermitant but seems to be getting worse. When I stop, the car jumps for a bit then stops. Acts like the torque converter is locking up. Runs fine other wise. Any ideas would be a help, thanks

 

Had the same sort of thing happen to an Olds I had. I don't know what the part is called, but it is accessible through an access plate in the bell housing area. There should be a wire (or maybe two) that go to that area. Unplug it. This will disable the overdrive and see if that does the trick. If it does, the overdirve thing is broke. Fairly simple and inexpensive fix.

 

More than likely the TCC (Torque Converter Clutch) solenoid is shorting to ground causing torque converter to stay in locked position as if it were in Overdrive. It is replaceable by pulling pan. There is a harness plugged into side of transmission you can unplug to check, but you will set a check engine light and lose shifting, but it will probably not go into lockup then. Have someone check for trouble codes on car to see if something else is causing it to go into lockup.