If you have a U joint, then you have replaced your rear DS as the stock has two Rzeppa joints which cannot be replaced by themselves. If you have a double cardan rear shaft, then the rear pinion angle MUST be properly set or you will blow the rear joint (most likely anyway) as it is not designed to run at high speed at an improper angle...so, do you have a U joint (double cardon shaft) in the rear? Did you properly set the rear pinion angle (using adj control arms)? If not, then you will need to do it.
08 JK 23S - Colorado Jeep Club No. 204
Too much to list - see my profile for details on build
16 JK Rubi with all the trimmings
NRA Life member
"It takes a special kind of stupid to believe criminals will follow gun laws."
I do not consider myself a smartass. I point out the obvious, search for the truth, and speak fluent sarcasm. I am, by experience, an accomplished curmudgeon.