2007-2009 Honda TRX300EX TRX300X service manual, Page 204Get this manual
CRANKCASETRANSMISSIONCRANKSHAFT INSPECTION GEARBUSHINGSHAFT
Check the gear shifter groove for abnormal wear or damageCheck the gear dogs and teeth for abnormal wear or damageIf there is damage to the gear dogs, check the slots or dogs on the corresponding engagement gear for damage
SHIFTER GROOVE
GEAR DOGS
Measure the I.Dof each gearSERVICE LIMITS: M4, M5, C2: 25.07 mm (0.987 in) C1, C3, Counter reverse: 28.07 mm (1.105 in) Reverse idle: 14.04 mm (0.553 in)