Originally Posted by JoelWisman
My personal belief is there is an issue here and I suspect it is related to either the hub or spacer.
I do not believe it has anything to do with the bearing quality because of the appearence of failed bearings and the fact that the same bearing is holding up on the same bike in other locations as well as other bikes.
I don't believe it is a design issue because too many bikes have bearings that are just fine at mileages that are the same or higher.
That and the fact that it tends to be the disc side rear bearing that keeps failing as well as the unusual patern of the bearing galling on the side of the race is what makes me think it is a missalignment or incorrect preload that is causing these failures.
The disc side of my bikes rear bearing began feeling grity at 5600 miles and is now getting loose.
Any thoughts on how to measure if the bearing is cocked or incorrectly preloaded? I am thinking machine shop but would love it if I could measure it in-house.
P.S. To the guy who's tech told him that BMW would not warranty his bearing. Your tech is speaking beyond his pay grade. The correct process is for the service manager to submit a claim and wait the 2 or so days to get a reply which may be a request for more info but on this I suspect would just be a green light. A service manager can not speak for PUMA or NA, a tech sure as hell can't.
The problem is and I suspect this will apply to the techs also, we do not have the design specs of how long the axle tube is supposed to be, depth of of the hub where the bearing is fitted and what the crush factor is supposed to be for the axle tube if there is one at all.
Some things you could measure is, if the hub is concentric where the bearing fits and if there is any space between the circlip and the bearing. I suppose if the spacer and the left bearing was fitted (spacer flange on that side) then look at the right side w/o the bearing and do a visual. The space being grossly too long or short may lend a clue, but again we don't know how it is supposed to be.