2004 YAMAHA YZ85 Rear shock absorber

3 - 27
INSP
ADJ
REAR SHOCK ABSORBER INSPECTION

STANDARD POSITION:
This is the position which is back by the spe-
cific number of clicks from the fully turned-in
position.
CAUTION:
Do not force the adjuster past the minimum
or maximum extent of adjustment. The
adjuster may be damaged.
WARNING
Always adjust each front fork to the same
setting. Uneven adjustment can cause poor
handling and loss of stability.
3. Install:

Rubber cap
Extent of adjustment
Maximum Minimum
Fully turned in
position20 clicks out (from
maximum position)
Standard position:
YZ85: 10 clicks out
YZ85LW: 9 clicks out
EC36K000
REAR SHOCK ABSORBER INSPECTION
1. Inspect:

Swingarm smooth action
Abnormal noise/unsmooth action →
Grease the pivoting points or repair the piv-
oting points.
Damage/oil leakage → Replace.
5PA30620

3 - 28
INSP
ADJREAR SHOCK ABSORBER SPRING PRELOAD
ADJUSTMENT
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Remove:

Rear frame
3. Loosen:

Locknut 1
4. Adjust:

Spring preload
By turning the adjuster 2.
* For EUROPE
NOTE:

Be sure to remove all dirt and mud from
around the locknut and adjuster before
adjustment.

The length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
5. Tighten:

Locknut
6. Install:

Rear frame (upper)

Rear frame (lower) Stiffer
→Increase the spring preload.
(Turn the adjuster
2 in.)
Softer
→Decrease the spring preload.
(Turn the adjuster
2 out.)
Spring length (installed)
a:
YZ85: 215 mm (8.46 in)
*212 mm (8.35 in)
YZ85LW: 207 mm (8.15 in)
*212 mm (8.35 in)
Extent of adjustment:
202.5 ~ 218.5 mm
(7.97 ~ 8.60 in)
5PA30630
5PA30640
T R..26 Nm (2.6 m · kg, 19 ft · lb)
T R..16 Nm (1.6 m · kg, 11 ft · lb)

3 - 29
INSP
ADJREAR SHOCK ABSORBER REBOUND DAMPING FORCE
ADJUSTMENT
REAR SHOCK ABSORBER REBOUND
DAMPING FORCE ADJUSTMENT
1. Adjust:

Rebound damping force
By turning the adjuster 1.
Stiffer
a
→ Increase the rebound damp-
ing force. (Turn the adjuster
1 in.)
Softer
b
→ Decrease the rebound damp-
ing force. (Turn the adjuster
1 out.)
Extent of adjustment
Maximum Minimum
Fully turned in
position20 clicks out (from
maximum position)
5PA30650

STANDARD POSITION:
This is the position which is back by the spe-
cific number of clicks from the fully turned-in
position.
* For EUROPE
CAUTION:
Do not force the adjuster past the minimum
or maximum extent of adjustment. The
adjuster may be damaged.
Standard position:
YZ85: 6 clicks out
*12 clicks out
YZ85LW: 7 clicks out
*12 clicks out

3 - 30
INSP
ADJREAR SHOCK ABSORBER COMPRESSION DAMPING
FORCE ADJUSTMENT
REAR SHOCK ABSORBER COMPRESSION
DAMPING FORCE ADJUSTMENT
1. Adjust:

Compression damping force
By turning the adjuster 1.
Stiffer
a
→ Increase the compression
damping force. (Turn the adjuster
1
in.)
Softer
b
→ Decrease the compression
damping force. (Turn the adjuster
1
out.)
Extent of adjustment
Maximum Minimum
Fully turned in
position20 clicks out (from
maximum position)
5PA30660

STANDARD POSITION:
This is the position which is back by the spe-
cific number of clicks from the fully turned-in
position. (Which align the punch mark a on
the adjuster with the punch mark b on the
bracket.)
* For EUROPE
CAUTION:
Do not force the adjuster past the minimum
or maximum extent of adjustment. The
adjuster may be damaged.
Standard position:
YZ85: About 9 clicks out
*About 12 clicks out
YZ85LW: About 7 clicks out
*About 12 clicks out
5PA30670

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CHASSWINGARM
EC570000
SWINGARM
5PAR0019
Extent of removal:
1 Swingarm removal
Extent of removal Order Part name Q’ty Remarks
SWINGARM REMOVAL
WARNING
Support the machine securely so there is no
danger of it falling over.
Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Real wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Brake hose holder
Rear brake caliper
Drive chainRefer to “FRONT BRAKE AND REAR
BRAKE” section.
1 Drive chain support 1
2 Bolt (connecting rod) 1 Hold the swingarm.
3 Bolt (rear shock absorber-relay
arm)1
4 Pivot shaft 1
5 Swingarm 1
1

5 - 57
CHAS
6. Install:

Swingarm 1

Pivot shaft 2

Washer 3

Nut (pivot shaft) 4
NOTE:

Apply the molybdenum disulfide grease on
the pivot shaft.

Insert the pivot shaft from right side.
7. Check:

Swingarm side play a
Free play exists → Replace collars.

Swingarm up and down movement b
Unsmooth movement/binding/rough spots
→ Grease or replace bearings, bushings
and collars.
5PA51820
T R..63 Nm (6.3 m · kg, 45 ft · lb)
5PA51830
8. Install:

Washer 1

Bolt (rear shock absorber-relay arm) 2
NOTE:

Apply the molybdenum disulfide grease on
the bolt.

Insert the bolt from left side.
5PA51840
T R..36 Nm (3.6 m · kg, 25 ft · lb)
9. Install:

Bolt (connecting rod) 1

Nut (connecting rod) 2
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
5PA51850
T R..53 Nm (5.3 m · kg, 38 ft · lb)
10. Install:

Drive chain support 1

Drive chain support cover 2

Bolt (drive chain support cover) 3

Nut (drive chain support cover) 4

Bolt (drive chain support) 5

Nut (drive chain support) 6
5PAR0026
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..16 Nm (1.6 m · kg, 11 ft · lb)
SWINGARM

5 - 58
CHASREAR SHOCK ABSORBER
EC580000
REAR SHOCK ABSORBER
5PA51870
Extent of removal:
1 Rear shock absorber removal
2 Rear shock absorber disassembly
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR SHOCK ABSORBER
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.
Seat Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
Silencer Refer to “EXHAUST PIPE AND
SILENCER” section in the CHAPTER 4.
1 Clamp (air cleaner joint) 1 Only loosening.
2Rear frame 1
3 Bolt (rear shock absorber-relay
arm)1 Hold the swingarm.
4 Bolt (rear shock absorber-frame) 1
5 Rear shock absorber 1
6 Locknut 1 Only loosening.
7 Adjuster 1 Only loosening.
8 Spring guide 1
9 Spring (rear shock absorber) 1
1
2

5 - 59
CHAS
HANDLING NOTE
WARNING
This rear shock absorber is provided with a
separate type tank filled with high-pressure
nitrogen gas. To prevent the danger of
explosion, read and understand the follow-
ing information before handling the shock
absorber.
The manufacturer can not be held respon-
sible for property damage or personal
injury that may result from improper han-
dling.
1. Never tamper or attempt to disassem-
ble the cylinder or the tank.
2. Never throw the rear shock absorber
into an open flame or other high heat.
The rear shock absorber may explode
as a result of nitrogen gas expansion
and/or damage to the hose.
3. Be careful not to damage any part of
the gas tank. A damaged gas tank will
impair the damping performance or
cause a malfunction.
4. Take care not to scratch the contact
surface of the piston rod with the cylin-
der; or oil could leak out.
5. Never attempt to remove the plug at
the bottom of the nitrogen gas tank. It
is very dangerous to remove the plug.
6. When scrapping the rear shock
absorber, follow the instructions on
disposal.
NOTES ON DISPOSAL (YAMAHA DEALERS
ONLY)
Before disposing the rear shock absorber, be
sure to extract the nitrogen gas from valve 1.
Wear eye protection to prevent eye damage
from escaping gas and/or metal chips.
WARNING
To dispose of a damaged or worn-out rear
shock absorber, take the unit to your
Yamaha dealer for this disposal procedure.
5PA51880
REAR SHOCK ABSORBER