YAMAHA TT600RE 2004 Service Manual

FRONT FORK
4-46
CHAS
OIL REPLACEMENT
NOTE:
The quality of the fork oil is of fundamental impor-
tance for obtaining the maximum performance
and functioning. For this reason it needs to be
replaced after the first 3÷4hours to eliminate any
residues due to the adaptation of the internal
components and successively every 8 hoursfor
motor-cross and every 20 hoursfor enduro.
Using oil with different technical specifica-
tions will compromise the good efficiency of
the fork.
CAUTION:
1. Generally clean the front fork.
2. Loosen:
•Cap bolt (inner tube)
3. Remove:
•Fork leg
4. Unscrew:
•Cap bolt (1) (completely)
NOTE:
Place the components in a clean area.
5. Withdraw:
•Seat (2)
•Spacer (3)
•Spring (4) (from the inner tube (5))
NOTE:
The spring, being immersed in oil could cause oil
to drip onto the work surface when withdrawn. It
is advisable therefore to withdraw it slowly and to
dry it with a clean cloth.
6. Pour the oil into a tray whilst at the same time moving the inner tube (1) backwards and for-
wards.
In order not to cause damage to the environ-
ment collect the used oil and take it to a col-
lection centre.
CAUTION:
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CHASFRONT FORK
4-47
7. Fill:
•Part of the new oil (with the fork leg in a
vertical position)
Recommended oil: Liqui Moly Racing suspension
oil SAE 7,5
Recommended oil: Liqui Moly Racing suspension
oil SAE 7,5
8. Using the inner tube pump back and forth until a regular drag is felt on the return stroke.
9. With the fork leg in a perfectly upright position, insert the inner tube (1) in the outer tube (2)
completely to the end of the stroke.
10. Finish topping up the oil bringing it to the pre- scribed level from the upper edge measured
with a graduated dipstick or ruler (3).
Oil level:
Standard 180 mm
Minimum 190 mm
Maximum 170 mm
From top of inner tube with inner tube fully
inserted without spring.
12. Screw:
•Cap bolts (5)
(on inner tube, without tighten)
13. Install:
•Fork leg
11. Insert:
•Spring (1) (into the inner tube (2))
•Seat (3)
•Spacer (4)
NOTE:
Usually there is no particular sense in which the
spring is mounted and so it may be inserted from
either end. If there is a hem, however mount it
keeping the hemmed parts towards the top.
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FRONT FORK
4-48
CHAS
Cap bolt (on inner tube): 20 Nm (2.0 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).
15. Tighten:
•Cap bolt (on inner tube)
14. 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)
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CHASFRONT FORK
4-49
CLEANING THE DUST SEAL
NOTE:
After using the motorcycle it is necessary to clean
the dust seal carefully in order to maintain the fork
at maximum efficiency.
In fact, if dust infiltrates to the inside of the dust
seal it can compromise the smoothness and
therefore the sensitivity of the fork, and also
cause the premature wear of the underlying oil
seal.
Just a few simple operations then, guided by the
following indications are necessary to maintain
the optimum functioning of the fork with time.
1. With a screwdriver prise the dust seal (1) from the oil seal seat (2) and then withdraw it using
force.
2. Using a low pressure jet of compressed air clean the inside of the dust seal and the oil
seal seat.
3. Insert the edge of a cloth under the lip and keeping the cloth steady, carefully clean the
lip by rotating the dust seal.
1
2
1
2
12
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FRONT FORK
4-50
CHAS
4. Using a small screwdriver take a small amount of silicon grease and insert it under
the lip paying attention not to scratch it.
Lubricate the dust seal by rotating it in such a
manner that the grease is distributed in the
inner part of the lip.
5. Remount the dust seal inserting it with force into the oil seal seat.
Check that the oil seal housing edge of the
dust seal adheres perfectly to the oil seal
seat.
CAUTION:
SEAL AND BUSH REPLACEMENT
NOTE:
To ensure maximum efficiency to the fork and
therefore a longer duration and greater safety,
every year (unless there are leakages) it is nec-
essary to replace all the seals and slide bushes.
To carry out this operation it is recommended to
use the proper tools.
To remove the fork leg from the steering unit,
the cap bolt, the spring and to drain and refill
the oil, follow the procedures indicated in the
preceding pages scrupulously.
CAUTION:
1. Drain:
•Fork leg oil Refer to “OIL REPLACEMENT”section.
2. Clamp:
•Fork leg in a vice (in a horizontal position)
Protect the outer tube with a clean rag to
avoid damaging.
CAUTION:
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CHASFRONT FORK
4-51
 

3. Insert an Allen key in the bolt (3) at the bottom of the outer tube and the special tool (1) with
the holder (2) on the damper cylinder assem-
bly and unscrew the bolt completely.
Before unscrewing the bolt ensure that the
end of the damper rod holder is correctly
engaged on the damper cylinder assembly.
CAUTION:
4. Remove:
•Damper cylinder assembly (from inner
tube)
5. Clean the inside of the outer tube and the out- side of the damper cylinder assembly with
petrol. T-handle (1):
90890-01326
Front fork damper rod holder (2): 90890-01460
Taking care not to let petrol enter the inside of
the damper cylinder assembly as it would
seriously compromise its functioning.
CAUTION:
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FRONT FORK
4-52
CHAS
6. Tightly clamp the fork leg horizontally fasten- ing it by caliper attachment on the outer tube.
7. Using a screwdriver prise the dust seal (4)from the edge of the oil seal seat (5).
Then withdraw the dust seal using force.
5
4
54
1
2
8. Remove:
•Snap ring (1) (using a screwdriver)
1
WARNING
Never tamper with the damper cylinder
assembly! Tampering with the damper cylinder
assembly by non authorized personnel can
compromise tha safety of the fork. In order not
to cause damage to the environment collect
the used oil and take it to a collection centre.
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CHASFRONT FORK
4-53
9. With a few sharp blows withdraw the inner tube (2) from the outer tube (3).
NOTE:
The oil seal (4), the washer (5), the outer tube DU
bush (6) and the inner tube DU bush (7) are
installed on the inner tube and must be removed
and replaced with new one.
10. Install:
•Outer tube DU bush (6) (new)
•Inner tube DU bush (7) (new)
Check that the inner tube bush (7) is inserted
correctly in its seat on the end of the inner
tube.
CAUTION:
11. Mount the tool (1) on the inner tube (2) with the side (3) matching the DU outer tube bush (4)
and clamp it keeping the two joints (5) at the
top and bottom (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
4
25
7
6
3
7
6
34
4
3
21
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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
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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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