Got new MIP x-duty rear axles for both mine and my sons Pede 4x4. Mine are fine, but I noticed a wicked vibration on his. Thought they were the rear bearing carriers at first and filed the plastic carriers a little. Still had a bad vibration.
Worked the suspension and observed it only vibrates when left rear arm is fully extended, vibration goes away when arm is compressed. Switched out parts with mine and was able to work it down to the upper female link attached to the rear differential.
I red loctited the pieces so I haven't been able to switch out the upper female shaft with another. It seems to bind when it is at the max angle with the arm fully extended.
All the other joints and shafts have no problem.