Originally posted by RC Donkey
1. What's the purpose of the Diff Outdrive Ring (75135) on the rear axle. The front doesn't have it and I've lost one of mine in a crash but haven't noticed any difference.
The front one-way uses steel outdrives, the purple ring helps keep the carbon plastic outdrives from flexing, which can make you lose the CVD bone and drive to that wheel. If you get a front ball diff you'll get another pair of purple rings. If you run stock you may not have a problem without the ring but with a mod motor on a large track you may eventually weaken the diff outdrives.
2. What's the purpose of the foam ring that goes on the ball joints?
They help keep dust and rubber from the tires (anything on the track) from getting under the ball cup and scratching the ball joint, or causing any binding.
3. Has anyone fitted the aftermarket aluminium block and hub set. Obviously a lot stronger but in a crash would it transfer the force of impact to another part of the chassis / suspension where as the carbon plastic one would have absorbed it or broke itself. I guess the ball joint would take some of that impact too.
I'd personally stick with the plastic parts. Plastic is lighter than aluminum so you don't lose performance, plus it's cheaper to replace.