Yamaha YZ250FX 2021 - Installing the Transmission

TRANSMISSION
5-75
2. Measure:
• Drive axle runout
(with a centering device and dial gauge “1”)
Out of specification  Replace the drive axle.
3. Check:
• Transmission gear
Blue discoloration/pitting/wear  Replace
the defective gear(s).
• Transmission gear dog
Cracks/damage/rounded edges  Replace
the defective gear(s).
4. Check:
• Transmission gear movement
Rough movement  Replace the defective
gear(s).
EAM30157
INSTALLING THE TRANSMISSION
1. Install:
• 6th pinion gear (27T) “1”
• 3rd/4th pinion gear (18T/21T) “2”
• Collar “3”
• 5th pinion gear (23T) “4”
• 2nd pinion gear (16T) “5”
(to the main axle “6”)
TIP
Before installation, apply molybdenum disulfide
oil to the inner and end surface of the idler gear
and to the inner surface of the sliding gear, then
install.
2. Install:
• 2nd wheel gear (29T) “1”
• 5th wheel gear (22T) “2”
• 3rd wheel gear (26T) “3”
• 4th wheel gear (24T) “4”
• 6th wheel gear (22T) “5”
• Collar “6”
• 1st wheel gear (31T) “7”
• O-ring “8”
(to the drive axle “9”)
TIP
• Before installation, apply molybdenum disul-
fide oil to the inner and end surface of the idler
gear and the collar and to the inner surface of
the sliding gear, then install.
• Apply the lithium-soap-based grease on the O-
ring.
3. Install:
• Washer “1”
• Circlip “2”
TIP
• Be sure the circlip sharp-edged corner “a” is
positioned opposite side to the washer and
gear “b”.
• Install the circlip with its ends “c” settled evenly
on the spline crests.
Drive axle runout limit
0.08 mm (0.0032 in)
M
3
4
2
1
6
5
New
M
M
M
2
3
4
5
6
7
9
8
1
New