2005-2009 Honda TRX400EX/TRX400X Service Manual, Page 197Get this manual
CRANKCASETRANSMISSIONCRANKSHAFT Apply engine oil to the inne surfaces and gu ide pins of the shift forksInstall the shift forks into gear shifter grooves with each identification mark facing up (right crankcase side) Apply engine oi to th uide grooves in th shift drum Install the shift drum, ali gning th sw itch plate co ntacting tab wi th the ne utral switch hole in he crankcaseSet the guide pin of each fork in to the guide grooves carefully
Apply engine oil to the shift fork shaftInsta ll the shift fo rk th ro ugh the sh ift forks and into the crankcase