Auto trans slipping in 3rd gear.

[kcub]

My 98 tj has started to slip when in 3rd gear. But reverse, 1st and 2nd work fine. I thought that rev and 3rd used the same clutch packs. It will go into 3rd normally, but when its under any load it revs up till you back off the throttle. Could this be a problem with the lock-up converter or do I have to do a rebuild?

 

[superj]

Is it the same trans as the Cherokee and grand Cherokee? If so, read up on torquing the bands because they might have stretched and are now letting the gears slip