2001-2006 Honda TRX 300EX Sportrax 300EX Factory Service Manual, Page 184Get this manual
CRANKSHAFTTRANSMISSION Check the needle bearings for damage, replace if necessary
Inspect the shift drum right journ81 for scoring, scratches, or evidence of insufficient lubricationCheck the shift drum grooves for wear or damage
Inspect the ball bearing 01 reverse shift drumInspect the cu t-out and g8ar of drum for damage