don't get to wrapped around all the ceramic bearing deal. I have never EVER used ceramic bearings, waaayyy over-rated. Since I started putting money into this hobby I can count how many bearingd I have blown, and most are on large scale RC. If they blow out fast is the quality of the bearing and not the material. All my 1/8th buggies have the same center bearing spec as the ARRMA Kraton and Talion and not once have they failed. Running a LRP .28 5 port on 20% nitro shredding spur and pinion gears every other or so tank, and still to this day they are fine, covered in dirt, mud, fuel. But its not my money that will be used.
** And I throw it out there for others to read who are new to this hobby. Get a pack of Avid, Losi w same specs and done.
The same thing for the shimming, I don't know, I may have a good rc, better materials etc. From large scale two stroke and now here, just follow manufacturer recommendations. Do remember, the company states SERVICE INTERVALS in the manual. If anything, upgrade to HD cnc diff housing. That is one thing that has helped on breakage on all two stroke applications. Instead of going crazy shimming, reinforce the diff. Its the flexing that destroys them, but I don't jump mine 20 feet in the air or slam them upside down like others enjoy to do so. Once again, on airsoft gearboxes players putJB weld on the exterior of the gearbox, besides shimming. I have my fair share of destroyed diffs on other rigs, it all stopped when a aluminum casing was installed.
