Hello

My friend in Germany has a Nitro 4x4 R/T his problem is that when you drive slow the rear wheels are shaking you will not feel it when you drive the Nitro but they find out that the axel is not total tight the rotors are moving to the side.
Is there a way to shime this or maybe a way to adjust it ?
When you drive sow it makes noise like the car have stand for a long time.