2005-2009 Honda TRX400EX/TRX400X Service Manual, Page 191Get this manual
II CRANKCASETRANSMISSIONCRANKSHAFT
Remove th il seals from the left cra nkcase
Remove the following from the idle shaft:lock washer (by prying it with screwdriver)reverse id Ie geargearbushing
REVERSE IDLE GEAR
BUSHING
Do n01 expand th e
Disassemble the ma inshaft and countershaftCO UNTERSHAFT