2006-2012 Honda TRX90 TRX90EX/X Service Manual, Page 180Get this manual
CRANKCASETRANSMISSIONCRANKSHAFT SHIFT DRUM Remove the guide pin clipsRemove the guide pinsthen remove the shift forksSHIFT FORKS
GUIDE PIN
GUIDE PIN CLIPS
INSPECTION
TRANSMISSION Check the gear dogs, dog holes and teeth for abnormal wear or lack of lubricationMeasure the I.Dof each gearSERVICE UMITS: M2: M4: C1: C3: 17.10 mm (0.673 in) 17.10 mm (0.673 in) 23.10 mm (0.909 in) 20.10 mm (0.791 in)