Again, I'm inclined to say, not being too lucky with scooter gears.
My XC 300iR let hear a grinding noise from its gear, which had to be examinated.
Muffler, carrier, RH shock and wheel off.
Result, specks of rust and brownish sludge outside exit driveshaft on the bearings sidewall, not to mention a rough feeling/noise when turned by hand.
Well, gear oil out, showed that there were only ca. 150ml instead of 230ml in it, my fault. Refilled 200ml. (oil level, dark, to be seen on pic)
Bought two oilseals, one for the gear, the second one for the carrier, where I renewed wheelbearing and oilseal too.
Size oilseals: 34-52-7 normsize €8,- each
Gear bearing: 6205 LU
Carrier bearing: 6204 LU, all normsize.€11,- each
Used the wellknown heating/ freezing method to change bearings and oilseals within gear and wheelcarrier.
All in all a four hour job inclusive a trip to my industrial shop for material (no coffee break).