steering YAMAHA YZ450F 2003 User Guide

5 - 45
CHAS
EC560000
STEERING
Extent of removal:1 Under bracket removal2 Bearing removal
Extent of removal Order Part name Q’ty Remarks
STEERING REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over.
Refer to “HANDLEBAR” section. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Number plate
Handlebar
Cable guide
Front fender
1 Steering shaft nut 1
2 Front fork 2 Refer to “FRONT FORK” section.
3 Handle crown 1
4 Ring nut 1 Use special tool.
Refer to “REMOVAL POINTS”.
5 Under bracket 1
6 Ball race cover 1
7 Bearing (upper) 1
8 Bearing (lower) 1 Refer to “REMOVAL POINTS”.
9Ball race
2Refer to “REMOVAL POINTS”.
2
1
STEERING

5 - 46
CHAS
EC563000
REMOVAL POINTS
EC563202
Ring nut
1. Remove:
Ring nut 1
Use the ring nut wrench 2.
WARNING
Support the steering shaft so that it may
not fall down.
Ring nut wrench:
YU-33975/90890-01403
EC563300
Bearing (lower)
1. Remove:
Bearing (lower) 1
Use the floor chisel 2.
ACHTUNG:CAUTION:
Take care not to damage the steering shaft
thread.
EC563400
Ball race
1. Remove:
Ball race 1
Remove the ball race using long rod 2
and the hammer.
EC564000
INSPECTION
EC564200
Steering shaft
1. Inspect:
Steering shaft 1
Bend/damage → Replace.
STEERING

5 - 47
CHASSTEERING
EC564101
Bearing and ball race
1. Wash the bearings and ball races with a
solvent.
2. Inspect:
Bearing 1
Ball race
Pitting/damage → Replace bearings
and ball races as a set.
Install the bearing in the ball races.
Spin the bearings by hand. If the bear-
ings hang up or are not smooth in their
operation in the ball races, replace
bearings and ball races as a set.
EC565000
ASSEMBLY AND INSTALLATION
Under bracket
1. Install:
Bearing (lower) 1
NOTE:
Apply the lithium soap base grease on the dust
seal lip and bearing inner circumference.
2. Install:
Ball race
Bearing (upper) 1
Ball race cover 2
NOTE:
Apply the lithium soap base grease on the
bearing and ball race cover lip.
3. Install:
Under bracket 1
NOTE:
Apply the lithium soap base grease on the
bearing, the portion a and thread of the steer-
ing shaft.

5 - 48
CHAS
4. Install:
Ring nut 1
Tighten the ring nut using the ring nut
wrench 2.
Refer to “STEERING HEAD INSPEC-
TION AND ADJUSTMENT” section in
the CHAPTER 3.
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
5. Check the steering shaft by turning it lock
to lock. If there is any binding, remove the
steering shaft assembly and inspect the
steering bearings.
6. Install:
Front fork 1
Handle crown 2
NOTE:
Temporarily tighten the pinch bolts (under
bracket).
Do not tighten the pinch bolts (handle crown)
yet.
7. Install:
Plain washer 1
Steering shaft nut 2
T R..145 Nm (14.5 m · kg, 105 ft · lb)
8. After tightening the nut, check the steer-
ing for smooth movement. If not, adjust
the steering by loosening the ring nut little
by little.
9. Adjust:
Front fork top end a
Front fork top end (standard) a:
Zero mm (Zero in)
STEERING

5 - 49
CHASSTEERING
10. Tighten:
Pinch bolt (handle crown) 1
Pinch bolt (under bracket) 2
ACHTUNG:CAUTION:
Tighten the under bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)