2004 YAMAHA TT600RE Service Manual

FRONT FORK
4-54
CHAS
12. The vice tightened, grip the outer tube and with a few strong blows hit it against the tool
(3) until the DU outer tube bush (4) is correct-
ly positioned in its seat.
13. Remove the fork leg from the vice and remove the tool (1). Insert the new washer (3) and the
new oil seal (4) as shown on the inner tube (2).
NOTE:
Apply lightweight lithium-soap base grease to the
oil seal before installing it.
14. Mount the tool (1) on the inner tube (2) with the side (5) matching the oil seal (4) and clamp it
keeping the two joints (6) at the top and bot-
tom (never towards the jaws of the vice) and
make it protrude by at least 40 mm at the
sides.
DU bush/oil seal driver (1): 90890-11043
54
3
~ 40 mm
124
5
43
21
15. The vice tightened, grip the outer tube and with a few strong blows hit it against the tool
(1). After each blow rotate the outer tube
slightly in order to install the oil seal (4) cor-
rectly and until it is completely inserted in its
seat.
1
2
64
3
~ 40 mm
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CHASFRONT FORK
4-55
16. Tightly clamp the fork leg horizontally fasten- ing it by caliper attachment on the outer tube.
17. Install:
•Snap ring (1)
Check that the snap ring is correctly seated.
CAUTION:
18. Install:
•Dust seal (1) (new)
NOTE:
Apply lightweight lithium-soap base grease to the
dust seal before installing it.
NOTE:
Taking care to insert completely the dust seal (1)
with force in the outer tube (2).
1
1
 

2
1
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FRONT FORK
4-56
CHAS
OIL LEAKAGE FROM DUST SEAL
If there is a leakage of oil from between the dust
seal (1) and the inner tube (2) replace the oil seal
(refer to “SEAL AND BUSH REPLACEMENT”
section).
ANOMALOUS HYDRAULIC BRAKING
If the fork shows an anomalous hydraulic braking
effect it is necessary to overhaul the damper cylin-
der assembly.
WARNING
Never tamper with the damper cylinder
assembly! This operation should be done by
authorized personnel. Tampering with the
damper cylinder assembly by non authorized
personnel can compromise the safety of the
front fork. The building firm will not assume
any responsibility for any damages resulting
from such action.
2
1
19. Insert:
•Damper cylinder assembly (in the inner
tube)
20. Insert an Allen key in the bolt (3) at the bot- tom of the outer tube and the special tool (1)
with the holder (2) on the damper cylinder
assembly and screw the bolt completely.
During tightening the bolt ensure that the end
of the damper rod holder is correctly engaged
on the damper cylinder assembly.
CAUTION:
21. Fill:
•Fork leg oil
Refer to “OIL REPLACEMENT”section. T-handle (1):
90890-01326
Front fork damper rod holder (2): 90890-01460
Damper cylinder assembly bolt (3):25 Nm (2.5 kgm)
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CHASFRONT FORK
4-57
FRONT FORK INSPECTION
The front fork has a very sophisticated inter-
nal construction and is particularly sensitive
to foreign bodies.
Use enough care to prevent foreign bodies
entering when replacing oil or disassembling
and reassembling the front fork.
CAUTION:
1. Inspect:
•Cap bolt (inner tube)
Wear/Damage ➔Replace.
•O-Rings
Damage ➔Replace.
2. Measure:
•Fork spring free length (a)
Out of specification ➔Replace.
Fork spring free length: 530 mm
Inner tube bending limit:0.2 mm
3. Inspect:
•Inner tube surface
Score marks ➔Repair or replace.
Use #1.000 grit wet sandpaper.
Damaged oil seal surface ➔Replace.
•Inner tube bending
Out of specification ➔Replace.
Use a dial gauge (1).
NOTE:
The bending value is shown by one half of the dial
gauge reading.
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FRONT FORK
4-58
CHAS
WARNING
Do not attempt to straighten a bent inner tube
as this may have dangerous consequences.
4. Inspect :
•Outer tube (1)
Score marks/Wear/Damage ➔Replace.
5. Inspect:
•Cap bolt
•O-ring
Wear/Damage ➔Replace.
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CHASFRONT FORK
4-59
FRONT FORK INSTALLATION
1. Install:
•Front fork (1)
Temporarily tighten the pinch bolts (lower).
2. Tighten:
•Cap bolt
Cap bolt: 20 Nm (2.0 kgm)
NOTE:
Do not tighten the pinch bolt (upper) yet.
3. Adjust:
•Front fork top end (a)
Front fork top end (a)
(Standard): 0 mm
4. Tighten:
•Pinch bolt (upper and lower bracket)
Pinch bolt (upper bracket): 28 Nm (2.8 mkg)
Pinch bolt (under bracket): 23 Nm (2.3 mkg)
NOTE:
Always tighten the lower pinch bolt (to the pre-
scribed torque) and then the upper one (to the
prescribed torque) and then retighten the lower
one (to the prescribed torque).
5. Install:
•Front wheel
•Caliper
•Brake hose
•Tachometer cable
Refer to “FRONT WHEEL” and “FRONT
BRAKE” sections in this CHAPTER.
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4-60
FRONT FORKCHAS






ADJUSTING THE FRONT FORK
This front fork is equipped with spring pre-load ad-
justing bolts.
WARNING
Always adjust both fork legs equally, other-
wise poor handling and loss of stability may
result.
Adjust the spring preload as follows.
To increase the spring preload and thereby hard-
en the suspension, turn the adjusting bolt on each
fork leg in direction a. To decrease the spring
preload and thereby soften the suspension, turn
the adjusting bolt on each fork leg in direction b.
Setting
Minimum (soft) 1-2-3
Standard 4
Maximum (hard) 5-6-7-8-9-10
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CHAS
4-61
STEERING
Order Job name/Part name Q.ty Remarks Steering removal Remove the parts in order.
Park the motorcycle on a level surface.
WARNING
Securely support the motorcycle to pre-
vent it falling over.
Front wheel Refer to “FRONT WHEEL REMOVAL” sec- tion.
Fork legs Refer to “FRONT FORK” section.
1 Cowling/Meter unit 1 Displace.
2 Front fender 1
3 Handle upper holder 2
4 Handle lower holder 1
5 Handlebar 1 Displace.
6 Nut 1
7 Upper bracket 1
8 Special washer 1
TIGHTENING PROCEDURE
• Initial tightening 38 Nm (3.8 mkg)
• Loosen 1 turn
• Final tightening 4 Nm (0.4 mkg)
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