That's a pain! The Baja Rey guys are getting that on 3S and I think you might be one of the first unfortunate RR owners!
It could have simply been the mesh or a failed bearing but the reported cures are:
Careful shimming of the diff pinion and crown gear which a number say fixes everything.
Custom alum SSD or Metal Concepts third member as they are much more solid and have bigger bearings. They are very affordable.
Full housing like VP or MC which would be totally bulletproof but not cheap.
I think the thing to consider is that the RR on 2S is as fast as a Yeti on 3S so it's dementedly quick on 3S and TBBH, the housings aren't built for crazy speeds (they are far too thin). You will likely chew out the front bulkhead too eventually if your rear is going on 3S. No one makes this bit yet but I feel that the RR with a VP or MC rear and a alum bulkhead/gearbox housing would be a seriously tough truck and the additional cost pales compared to how weak the Yeti is and what that thing needs just to hold together at the speed of a 2S RR.
Originally Posted by
FelixRockRey
Update from me:
I finally had the time to look through center and rear diff.
The trouble was caused by the rear diff - the backside of the metal pinion gear had literally milled itself into the inner part of the front plastic housing of the rear axle and therefore had enough play (about 1 mm) to slide forward and backward. This was enough that it would slip off/loose contact to the rear diffs spur-gear when high torque / accelaration occured...
I dissasambled everything, sandpapered away all ridges from the pinion gear and simply put a metal washer between the plastic housing and the pinion gear. Now hopefully this should last a while -but some heavy grease between both parts and mounted the rear drifte shaft again (had to mount the shaft by 90° and drill an new hohle into the mounting end since the original hohles of the pinion gear shaft and the drive shaft no did not lign up exactly any more...
And now the RR rocks again!
I also ordered a new plastic housing, but I assume that it will be also be milled away at a certain level of time - so I hope my washer solution will last longer!
I also change the programm for the start mode from level 9 to level 6, so the initial punsh onto the driveshafts and diffs going at 3S is not as hard as before and this will hopefully prolong the lifetime of the drivetrain components.