When dose it make the noise? First you want to know if it's torque related or suspension related. will it do it in 2 wheel and 4 wheel drive? On or off the gas? On bumps? On or off the brakes?
We can't see your RZR so the info you give us is the only clues we get.
I work on cars for a living. I have some people that can't tell me anything other than "it's not right" and have others that can tell me every little detail about their problem. Guess which one gets fixed with 100% accuracy.