Contamination is rare - if it is bearing wear you would see some in the oil - try tipping the oil out and have a look to see of it is clear. Pretty sure the Transrotor uses classic bronze sleeves/steel shaft.
I have used CRC electroclean to flush bearings ( spray nozzle has a tube attachment ), followed by CRC CO contact cleaner to remove any residue.
I always smear a little oil on the spindle ( particularly the tip ) before insertion to ensure no scouring occurs when inserting. This is important.