Checking The Wheel Axle; Installing The Front Wheel; Checking The Wheel; Checking The Brake Disc - Yamaha YZ450F(X) Owner's Service Manual

HANDLING NOTE
Support the machine securely so
there is no danger of it falling over.
REMOVING THE REAR WHEEL
1. Remove:
• Wheel "1"
Push the wheel forward and remove
the drive chain "2".
REMOVING THE WHEEL BEARING
1. Remove:
• Bearing "1"
Remove the bearing using a general
bearing puller "2".

CHECKING THE WHEEL

1. Measure:
• Wheel runout
→
Out of limit Repair/replace.
Wheel runout limit:
Radial "1": 2.0 mm
(0.08 in)
Lateral "2": 2.0 mm
(0.08 in)
2. Inspect:
• Bearing
Rotate inner race with a finger.
→
Rough spot/seizure
Replace the bearings, oil seal and
wheel collar as a set.

CHECKING THE WHEEL AXLE

1. Measure:
• Wheel axle bends
Out of specification
Use the dial gauge "1".
Wheel axle bending limit:
The bending value is shown by one
half of the dial gauge reading.
Do not attempt to straighten a bent
axle.

CHECKING THE BRAKE DISC

1. Measure:
• Brake disc deflection (only rear
brake disc)
Use the dial gauge "1".
Out of specification
wheel runout.
If wheel runout is in good condi-
tion, replace the brake disc.
Brake disc deflection lim-
it:
2. Measure:
• Brake disc thickness "a"
Out of limit
Brake disc thickness:
Replace.

FRONT WHEEL AND REAR WHEEL

→
Replace.
0.5 mm (0.020 in)
→
Inspect
Rear:
<Limit>: 0.15 mm
(0.006 in)
→
Replace.
Front:
3.0 mm (0.12 in)
<Limit>: 2.5 mm (0.10
in)
Rear:
4.0 mm (0.16 in)
<Limit>: 3.5 mm (0.14
in)
5-3

INSTALLING THE FRONT WHEEL

1. Install:
• Bearing (left) "1"
• Spacer "2"
• Bearing (right) "3"
• Oil seal "4"
• Apply the lithium soap base grease
on the bearing and oil seal lip when
installing.
• Use a socket that matches the out-
side diameter of the race of the
bearing.
• Left side of bearing shall be in-
stalled first.
• Install the oil seal with its manufac-
ture's marks or numbers facing out-
ward.
Do not strike the inner race of the
bearing. Contact should be made
only with the outer race.