I cannot see how the shocks would play a role in your diff problems. Although I have not had to open my diff's up I have worked on my 1973 Mustang diff. Usually when you are having ring and pinion problems on a vehicle is has to do with the alignment of the two. In cars they use shims to obtain the correct backlash needed. Is it possible that a bearing is bad and not allowing the ring and pinion to mate up correctly? Again I cannot see how your shock (suspension) would play a part in this. I hope this helped.