XRAY - Model racing cars

ok I started with an 808/09 .I up dated the car to the 2010 I also run the monster slipper/diff ,alum rear brace,new chassis, to try n stop this... the inner bearing "rear diff" lost its shield as well can it jam and chip it? .. I only had40 min run time on the center bearings.. even with the bigger bearings they come apart like the small.... I can't offord to replace gears every month

You are supposed to take the shield off the bearings in the front and rear diffs. There is no reason you should be chipping the gears in the front and rear. I have been the original front and rear diffs for 2 years now.

i was never told to do so..

Yup, no shields in the gear boxes. Just on the outside sides of the diff cases.

I'm trying Boca revolutions bearings with shields, but I doubt they'll be any better.