U- Joint question

Hey everyone, my s13 has a vibration in the back of the car ? i took down the drive shaft and the u joint is sticking, is it replaceable ? and do i need special tools ?

Vibrations can likely be from either that knuckle or the hanger bearing if the s13’s have them. The R32 hanger bearing fails, and causes odd vibrations at certain rpm ranges.

Is this vibration happening all the time?

I actually have the same problem kinda… except i know its not my diff for sure cause i just swapped it out. basically if i’m going about 40km/hr, no matter what gear i’m in, or even if i’m in neutral, i get a wierd vibration coming from the rear end…i haven’t had a chance to check anything yet, but i thought i’d throw it out there.