93 ZJ Automatic Hard Gear Change

[blackbird24]

Hi there,

Im wondering if anyone else experiences this with their Jeep. When I am in stop and go traffic I find my transmission sometimes changes gear harshly. It happens when the gear is going to change but I dont give it anymore gas so it just thumps into the next gear. Where as if I give it just a little more gas it will change to the next gear smoothly. I find myself giving it gas just to change gears smoothly only to have to hit the brakes so I dont hit the vehicle in front of me in stop and go traffic. The thump into gear is not from the transmission though its from the rear diff area. So I guess what I am saying is the transmission changes gears fine but its how the rear diff reacts when not given additional gas just before the gear changes. Sorry if this sounds confusing I wish I could describe it better.

Outside of this scenario both the transmission and rear diff function as they should.

Any thoughts, comments or remedies?

Thanks.

Al

[Cam7]

The First thing I would suggest is to change the Trans fluid and the Transfer Case fluid. Then check the U joints for any play, U might have a bad U Joint that might be causing that thump.