2004 YAMAHA YZ250LC Shock

5-57
CHASSWINGARM
10. Tighten:
9Nut (connecting rod) 1
11. Tighten:
9Nut (relay arm) 1
80 Nm (8.0 m•kg, 58 ft•lb)
80 Nm (8.0 m•kg, 58 ft•lb)
8. Install:
9Bolt (connecting rod) 1
9Plain washer 2
9Nut (connecting rod) 3
NOTE:
9Apply the molybdenum disulfide grease on the
bolt.
9Do not tighten the nut yet.
9. Install:
9Bolt (rear shock absorber-relay arm) 1
9Nut (rear shock absorber-relay arm) 2
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
53 Nm (5.3 m•kg, 38 ft•lb)
7. Check:
9Swingarm side play
a
Free play exists  Replace thrust bearing.
9Swingarm up and down movement b
Unsmooth movement/Binding/Rough
spotsGrease or replace bearings, bushes
and collars.
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5-59
CHASREAR SHOCK ABSORBER
Extent of removal Order Part name Q’ty Remarks
REAR SHOCK ABSORBER
REMOVAL
Preparation forHold the machine by placing the
removalsuitable stand under the engine.
SeatRefer to “SEAT, FUEL TANK AND
SIDE COVERS” section.
SilencerRefer to “EXHAUST PIPE AND
SILENCER” section.
1 Clamp (air cleaner joint) 1 Loosen the screw (air cleaner joint).
2 Rear 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
7 Adjuster 1
8 Spring guide (lower) 1
9 Spring guide (upper) 1
10 Spring (rear shock absorber) 1
11 Bearing 2 Refer to “REMOVAL POINTS”.
2
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Support the machine securely so there is no dan-
ger of it falling over.
Extent of removal:1Rear shock absorber removal 2Rear shock absorber disassembly
1
56 Nm (5.6 m•kg, 40 ft•lb)
53 Nm (5.3 m•kg, 38 ft•lb)
32 Nm (3.2 m•kg, 23 ft•lb)
EC580000
REAR SHOCK ABSORBER
29 Nm (2.9 m•kg, 21 ft•lb)
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5-60
CHASREAR SHOCK ABSORBER
EC586000
HANDLING NOTE
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This shock absorber is provided with a
separate type tank filled with high-pressure
nitrogen gas. To prevent the danger of ex-
plosion, read and understand the following
information before handling the shock ab-
sorber.
The manufacturer can not be held respon-
sible for property damage or personal in-
jury that may result from improper han-
dling.
1. Never tamper or attempt to disassemble
the cylinder or the tank.
2. Never throw the shock absorber into an
open flame or other high heat. The shock
absorber may explode as a result of ni-
trogen 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 sur-
face of the piston rod with the cylinder;
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 shock absorber, fol-
low the instructions on disposal.
EC587000
NOTES ON DISPOSAL (YAMAHA DEAL-
ERS ONLY)
Before disposing the 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.
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To dispose of a damaged or worn-out
shock absorber, take the unit to your
Yamaha dealer for this disposal procedure.
5XF-9-30-5D 5/6/03 6:37 PM Page 20

5-61
CHASREAR SHOCK ABSORBER
EC583000
REMOVAL POINTS
EC583320
Bearing
1. Remove:
9Stopper ring (upper bearing) 1
NOTE:
Press in the bearing while pressing its outer race
and remove the stopper ring.
2. Remove:
9Upper bearing 1
NOTE:
Remove the bearing by pressing its outer race.
EC584000
INSPECTION
EC584110
Rear shock absorber
1. Inspect:
9Damper rod 1
Bends/Damage Replace absorber
assembly.
9Shock absorber 2
Oil leaks Replace absorber assembly.
Gas leaks Replace absorber assembly.
9Spring 3
Damage Replace spring.
Fatigue Replace spring.
Move spring up and down.
9Spring guide 4
Wear/Damage Replace spring guide.
9Bearing 5
Free play exists/Unsmooth revolution/
Rust Replace. 3. Remove:
9Lower bearing 1
NOTE:
Remove the bearing by pressing its outer race.
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5-62
CHASREAR SHOCK ABSORBER
EC585111
Spring (rear shock absorber)
1. Install:
9Spring 1
9Spring guide (upper) 2
9Spring guide (lower) 3
2. Tighten:
9Adjuster 1
EC585000
ASSEMBLY AND INSTALLATION
EC585320
Bearing
1. Install:
9Upper Bearing 1
NOTE:
Install the bearing parallel until the stopper ring
groove appears by pressing its outer race.
cC
Do not apply the grease on the bearing
outer race because it will wear the rear
shock absorber surface on which the bear-
ing is press fitted.
2. Install:
9Stopper ring (upper bearing) 1
NOTE:
After installing the stopper ring, push back the
bearing until it contacts the stopper ring.
3. Install:
9Lower bearing 1
NOTE:
Install the bearing by pressing it on the side hav-
ing the manufacture’s marks or numbers.
Installed depth of the bearing a a
:
4 mm (0.16 in)
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5-63
CHASREAR SHOCK ABSORBER
EC5852B5
Rear shock absorber
1. Install:
9Dust seal 1
9O-ring 2
9Collar 3
NOTE:
9Apply the molybdenum disulfide grease on the
bearing.
9Apply the lithium soap base grease on the dust
seals, O-rings and collars.
2. Install:
9Bush 1
9Collar 2
9Dust seal 3
NOTE:
9Apply the molybdenum disulfide grease on the
bearing.
9Apply the lithium soap base grease on the
bush, collars and dust seals.
9Install the dust seals with their lips facing out-
ward.
3. Adjust:
9Spring length (installed) a
*For EUROPE
NOTE:
The length of the spring (installed) changes 1.5
mm (0.06 in) per turn of the adjuster.
cC
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
4. Tighten:
9Locknut 1
Spring length (installed) a
a
:
Standard
length
245 mm (9.65 in)
*268 mm (10.55 in)Extent of
adjustment
240.5~258.5 mm
(9.47~10.18 in)
*255.5~273.5 mm
(10.06~10.77 in)
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5-64
CHASREAR SHOCK ABSORBER
3. Install:
9Rear shock absorber
4. Install:
9Bolt (rear shock absorber-frame) 1
9Nut (rear shock absorber-frame) 2
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
5. Install:
9Bolt (rear shock absorber-relay arm) 1
9Nut (rear shock absorber-relay arm) 2
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
6. Install:
9Rear frame 1
9Bolt [rear frame (upper)] 2
9Bolt [rear frame (lower)] 3
7. Tighten:
9Screw (air cleaner joint) 1
56 Nm (5.6 m•kg, 40 ft•lb)
53 Nm (5.3 m•kg, 38 ft•lb)
29 Nm (2.9 m•kg, 21 ft•lb)
32 Nm (3.2 m•kg, 23 ft•lb)
5XF-9-30-5D 5/6/03 6:37 PM Page 28

7-21
SETTINGTUN
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When using a rear cushion other than cur-
rently installed, use the one whose overall
length a a
does not exceed the standard as
it may result in faulty performance. Never
use one whose overall length is greater
than standard.
åCoverage of spring by weight
∫Rider weight
1Soft
2Standard
3Stiff
Length a a
of standard shock:
490.5 mm (19.31 in)
5XF-9-30-7 4/22/03 8:56 AM Page 46