Nissan Repair: Nissan Narava D22 Model, wheeles, good shape

Question
I have a problem I think with the rear wheeles
When I go in reverse the back wheels seam to jump and if you do it on gravel it leaves small mounds then flat then mounds.
Is this the way diff locks work or do I have a problem ?  

Answer
Rosslp 1,

It could be that the idle is too high.  Try reverse when you have your foot firmly on teh brake pedal.  Second, make sure the bushings on the back suspension are in good shape and not worn out.  If the bushings are worn the rear end will jump when put into reverse.  Nothing to do with the differential locking or not.