wheel YAMAHA YZ85 2003 Owner's Manual

4 - 62
ENG
2. Install:

2nd wheel gear (32T) 1

6th wheel gear (25T) 2

3rd wheel gear (26T) 3

4th wheel gear (22T) 4

5th wheel gear (26T) 5

1st wheel gear (27T) 6
To drive axle 7.
NOTE:

Apply the molybdenum disulfide oil on the
1st, 2nd, 3rd and 4th wheel gears inner cir-
cumference and on the end surface.

Apply the transmission oil on the 5th and 6th
wheel gears inner circumference.
5PA41880
3. Install:

Washer 1

Circlip 2
NOTE:

Be sure the circlip sharp-edged corner a is
positioned opposite side to the washer and
gear b.

Be sure the circlip end c is positioned at
axle spline groove d.
5PA41900
5PA41890
4. Install:

Collar 1
NOTE:

Apply the lithium soap base grease on the oil
seal lip.

When installing the collar into the crankcase,
pay careful attention to the crankcase oil seal
lip.
5PAR0011
TRANSMISSION, SHIFT CAM AND SHIFT FORK

4 - 63
ENG
5. Install:

Main axle 1

Drive axle 2
To left crankcase.
5PA41920
Shift cam and shift fork
1. Install:

Shift fork 1 (L) 1

Shift fork 2 2

Shift fork 3 (R) 3

Straight pin 4
NOTE:

Mesh the shift fork #1 (L) with the 6th wheel
gear 5 and #3 (R) with the 5th wheel gear 7
on the drive axle.

Mesh the shift fork #2 with the 3rd/4th pinion
gear 6 on the main axle.
5PA41930
5PA41940
2. Install:

Shift cam 1
NOTE:
Apply the transmission oil on the shift cam.
5PA41950
TRANSMISSION, SHIFT CAM AND SHIFT FORK

5 - 1
CHAS
EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1 Front wheel removal
2 Wheel bearing removal
3 Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
1 Nut (front wheel axle) 1
2 Front wheel axle 1
3 Front wheel 1
4 Collar 2
5 Oil seal 2
6 Bearing 2 Refer to “REMOVAL POINTS”.
7 Brake disc 1
2
31
3
5PA50010

5 - 2
CHAS
EC598100
REAR WHEEL
5PAR0012
Extent of removal:
1 Rear wheel removal
2 Wheel bearing removal
3 Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Drive chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Rear wheel sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disc
1
2
31
3
FRONT WHEEL AND REAR WHEEL

5 - 3
CHAS
EC593000
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:

Wheel 1
NOTE:
Push the wheel forward and remove the drive
chain 2.
5PA50030
EC513201
Wheel bearing (if necessary)
1. Remove:

Bearing 1
NOTE:
Remove the bearing using a general bearing
puller 2.
5PA50040
EC594000
INSPECTION
EC514100
Wheel
1. Measure:

Wheel runout
Out of limit → Repair or replace.
2. Inspect:

Bearing
Rotate inner race with a finger.
Rough spot/seizure → Replace.
NOTE:
Replace the bearings, oil seal and wheel collar
as a set.
Wheel runout limit:
Radial 1: 2.0 mm (0.08 in)
Lateral 2: 2.0 mm (0.08 in)
5PA50050
5PA50060
FRONT WHEEL AND REAR WHEEL

5 - 4
CHAS
EC514200
Wheel axle
1. Measure:

Wheel axle bends
Out of specification → Replace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent axle.
Wheel axle bending limit:
0.5 mm (0.020 in)
5PA50070
Brake disc
1. Measure:

Brake disc deflection
Use the dial gauge 1.
Out of specification → Inspect wheel
runout.
If wheel runout is in good condition, replace
the brake disc.
2. Measure:

Brake disc thickness a
Out of limit → Replace.
Brake disc deflection limit:
0.15 mm (0.006 in)
Brake disc thickness:
3.0 mm (0.12 in)
<Limit>: 2.5 mm (0.10 in)
5PA50080
FRONT WHEEL AND REAR WHEEL

5 - 5
CHAS
EC595000
ASSEMBLY AND INSTALLATION
Front wheel
1. Install:

Bearing (left) 1

Spacer 2

Bearing (right) 3

Oil seal 4
NOTE:

Apply the lithium soap base grease on the
bearing and oil seal lip when installing.

Use a socket that matches the outside diam-
eter of the race of the bearing.

Left side of bearing shall be installed first.

Install the oil seal with its manufacture’s
marks or numbers facing outward.
CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
2. Install:

Brake disc 1

Bolt (brake disc) 2
5PA50090
5PA50100
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
3. Install:

Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
5PA50110
4. Install:

Wheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.
5PA50120
FRONT WHEEL AND REAR WHEEL

5 - 6
CHAS
5. Install:

Washer 1

Wheel axle 2
NOTE:
Apply the lithium soap base grease on the
wheel axle.
5PA50130
6. Install:

Washer 1

Nut (wheel axle) 2
5PA50140
T R..70 Nm (7.0 m · kg, 50 ft · lb)
Rear wheel
1. Install:

Bearing (left) 1

Circlip 2

Spacer 3

Bearing (right) 4

Oil seal 5
NOTE:

Apply the lithium soap base grease on the
bearing and oil seal lip when installing.

Install the bearing with seal facing outward.

Use a socket that matches the outside diam-
eter of the race of the bearing.

Left side of bearing shall be installed first.

Install the oil seal with its manufacture’s
marks or numbers facing outward.
CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
5PA50150
FRONT WHEEL AND REAR WHEEL

5 - 7
CHAS
2. Install:

Brake disc 1

Bolt (brake disc) 2
NOTE:
Tighten the bolts (brake disc) in stage, using a
crisscross pattern.
5PA50160
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
3. Install:

Rear wheel sprocket 1

Bolt (rear wheel sprocket) 2

Washer (rear wheel sprocket) 3

Nut (rear wheel sprocket) 4
NOTE:
Tighten the nuts (rear wheel sprocket) in
stage, using a crisscross pattern.5PA50170
T R..42 Nm (4.2 m · kg, 30 ft · lb)
4. Install:

Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
5PA50180
5. Install:

Wheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.
5PA50190
6. Install:

Drive chain 1
NOTE:
Push the wheel 2 forward and install the drive
chain.
5PA50200
FRONT WHEEL AND REAR WHEEL

5 - 8
CHAS
7. Install:

Right drive chain puller 1

Left drive chain puller 2

Washer 3

Wheel axle 4
NOTE:

Apply the lithium soap base grease on the
wheel axle.

Insert the wheel axle from right side.5PAR0013
8. Install:

Washer 1

Nut (wheel axle) 2
NOTE:
Temporarily tighten the nut (wheel axle) at this
point.
5PAR0014
9. Adjust:

Drive chain slack a
Refer to “DRIVE CHAIN SLACK ADJUST-
MENT” section in the CHAPTER 3.
Drive chain slack:
35 ~ 45 mm (1.4 ~ 1.8 in)
5PA50230
10. Tighten:

Nut (wheel axle) 1

Locknut 2
5PAR0015
T R..90 Nm (9.0 m · kg, 65 ft · lb)
FRONT WHEEL AND REAR WHEEL