I have a new issue with my wagoneer....the last couple of days I have a occasionally had a violent "clunk" from my tranny when it shifts from 3rd to 4th at low RPMS.
If I accelerate through 45 mph and stay there, i dont get the clunk. But if Im cruising down backroads at about 35 and it want to shift....its not so smooth.

I have a really bad sinking feeling about this.

Thanks in advance for any advice.

(AW4 tranny I think.....89 XJ Waggy automatic.)

 

could just be a bad drive shaft u-joint.
but don't rule out the tranny mount.

get under and start checking for excessive play.
to check the tranny mount, push up on the tail stock of the t-case. it shouldn't push up very far.

 

I got under there and tried moving things around and got zero give. Its starting to happen at different speeds.

Out of desperation I put 1/2 pint of SeaFoam in the tranny to see if is smooths out a bit.

 

After some research I think I have figured out the problem. Im pretty sure the Torque Converter is failing to lock-up properly. At this point I dont know if it is the TCC or the Converter itself.

Is there anyway to temporarily disable the lock-up? At least until I cant get it looked at next week. Unfortunatley this is my daily driver and I'll be working all weekend.