i have a 94 xj, i have done the u bolt conversion on the rear driveshaft the u joint keeps coming off the yoke when i'm wheelin it only does it on one hill, the only reason i keep trying is my other cherokee buddies go up it and make it and they have a 4 inch lift like myself with stock u joints the only difference in our cherokees is there locked in the rear an i'm not can anyone tell me what i could do to keep the u joint in the straps

 

Sounds like the tabs (on the yokes) might be busted off. Pics would help.

 

what is this upgrade you speak of?

 

Your u-joint is coming out of your yoke? Sounds like a worn out yoke. Do you have any play in it?