Yamaha YZ450FY 2009 Owner's Service Manual page 248

CHECKING THE REAR SHOCK ABSORBER
1. Inspect:
• Damper rod "1"
Bends/damage → Replace rear shock ab-
sorber assembly.
• Shock absorber "2"
Oil leaks → Replace rear shock absorber as-
sembly.
Gas leaks → Replace rear shock absorber
assembly.
• Spring "3"
Damage → Replace spring.
Fatigue → Replace spring.
Move spring up and down.
• Spring guide "4"
Wear/damage → Replace spring guide.
• Spring seat "5"
Cracks/damage → Replace.
• Bearing "6"
Free play exists/unsmooth revolution/rust →
Replace.
REAR SHOCK ABSORBER
INSTALLING THE BEARING
1. Install:
• Upper bearing "1"
Install the bearing parallel until the stopper ring
groove appears by pressing its outer race.
Do not apply the grease on the bearing out-
er race because it will wear the rear shock
absorber surface on which the bearing is
press fitted.
2. Install:
• Stopper ring (upper bearing) "1"
After installing the stopper ring, push back the
bearing until it contacts the stopper ring.
3. Install:
• Lower bearing "1"
Install the bearing by pressing it on the side
having the manufacture's marks or numbers.
Installed depth of the bearing "a":
4 mm (0.16 in)
5-57