[fredjacksonsan]

Probably cheaper (and easier!) to simply have the trans rebuilt.

There are a lot of threads here in the Jeep forums with the same discussion, and there are a lot more headaches than just swapping the transmissions including output shaft length, electrical harness differences and whether the new trans will mate up to the engine, to name a few.

Before you go and do anything, you might want to consider that fresh fluid can make a huge difference in your transmission.

The lurch might be drivetrain slack; how are your Ujoints?