It's a 1.5 or a 2 way diff, it has been rebuild 600km ago and one wheel is feels like it's skipping or constantly going over a pothole, I know for a fact it's not the wheels/tires because I tried 2 sets of wheels.

from what I read online my diff is fucked, how can this be after like 600km ?

 

The shop that rebuilt my diff put in the wrong fluid. As soon as I put in redline lightweight shockproof it fixed the problem