Ansmann X4 Pro Diff problems!!!

[Gillblade]

Ran my X4 pro for the first time this weekend at a local race here in Sweden... having some issues wit the ball diff, only after approx 4-6 packs they are crap and feels like there are tons of dirt in them. disassemble them and there are big groves in the diff rings. Is there any other diff-rings and balls u can use from another brand? Seems like the AR stuff isn't the best in quality.

Anyone got some tips for building them and tips of "upgrade" parts!!!

Also is there anyone who know the spring rate on the standard black springs that comes with the kit?

Best regards
Andreas G
Sweden