1999-2002 TRX400EX Fourtrax Service Manual, Page 150Get this manual
CRANKCASETRANSMISSIONCRANKSHAFT Check the gears for freedom of movement or rotation on the shaftEngagethe mainshaft and countershaft gears
MAINSHAFT
COUNTERSHAFT If removed, installthecrankshaftbalancer (page11-1')Apply oil to the countershaft oil seal lipInstall the mainshaft and countershaft assemblies as set into the left crankcaseMAINSHAFT AND COUNTERSHAFT
8e sure to install the thrust washers
NOTE: Each shift fork has an identification mark; for the left fork, for the centerfork and for the right fork