I bought a spare complete diff (individual parts) for my Associatted 12r5.1 and it needs to be done up noticeably tighter to stop the diff from slipping compared to the one that came in the kit. Both diffs are built identically and I swapped a bunch of bits around and it turns out its the main axle that is causing the issue.

Is this common?

Will the Xray full Aluminium rear axle fit? Maybe with all of the Xray parts?
http://www.teamxray.com/teamxray/pro...20Axle%20Shaft