The bearing in question is always turning at the same speed (in relation to the motor/tranny gear) if the shifter is in neutral or low or high because its the secondary shaft. Your just sliding the hub coupler when you shift it and not actually changing the speed that particular bearing is spinning.
As for the oil clearance on the rear case, I think Marlin recommends in his dual case instructions that it should be .004" to .010" for the new crawler input shaft clearance. I would have to assume its suppose to be the same dimension for the rear shaft also but I don't know. Also I'm not sure what would happen if the clearance is too big as opposed to it being too small, the bearing would fry.
UPDATE: I just got everything back together, filled it will fluid 80/90W GL5 gear oil and did the same test as before and not rattle noise??? It appears I fixed it but I didn't change anything. The only thing I did was take it appart, clean it up, lube it and re-assembly it. So now I'm thinking that it "could be" the splines rattling from one conection to the other since I lubed those up with a high pressure grease during assembly or a bearing was dry and now it has lube..... I really don't know.
Will be interesting if Marlin can shed any light on this ?? ??
