Yamaha TDM850 User Manual page 131

6»10 Frame, suspension and final drive
7.6 Withdraw the damping adjuster rod
(A), then remove the spring seat (B) and
withdraw the spring (C)
hold the locknut and thread the pre-load adjuster
(with the top bolt if not removed) off the damper
rod.
6 Remove the damping adjuster rod from the
centre of the damper rod, then remove the spring
seat and withdraw the spring from the tube,
noting which way up it fits (see illustration).
7 Invert the fork leg over a suitable container
and pump the fork and the damper rod vigorously
to expel as much fork oil as possible.
8 Remove the previously slackened damper rod
bolt and its copper sealing washer from the
bottom of the slider. Discard the sealing washer
as a new one must be used on
7.12 To separate the inner and outer fork
tubes, pull them apart firmly several times
- the slide-hammer effect will pull the
tubes apart
7.13 The oil seal (1), washer (2), top bush
(3) and bottom bush (4) will come out with
the fork tube
7.10 Prise out the dust seal using a flat-
bladed screwdriver
reassembly. If the damper rod bolt was not
slackened before dismantling the fork, use the
Yamaha service tool (90890-01447) to prevent
the damper rod from turning. This tool is passed
down through the fork tube and engages the
damper rod head; a similar tool can be easily
made in the home workshop.
9 Invert the fork and withdraw the damper rod
from inside the fork tube (see illustration
7.20a).
10 Carefully prise out the dust seal from the top
of the slider to gain access to the oil seal
retaining clip (see illustration). Discard the dust
seal as a new one must be used.
11 Carefully remove the retaining clip, taking
care not to scratch the surface of the tube (see
illustration).
12 To separate the tube from the slider it is
necessary to displace the top bush and oil seal.
The bottom bush should not pass through the top
bush, and this can be used to good effect. Push
the tube gently inwards until it stops against the
damper rod seat. Take care not to do this forcibly
or the seat may be damaged. Then pull the tube
sharply outwards until the bottom bush strikes
the top bush. Repeat this operation until the top
bush and seal are tapped out of the slider (see
illustration).
13 With the tube removed, slide off the oil seal,
washer and top bush, noting which way up they
fit (see illustration). Discard the oil seal as a
new one must be used. Caution: Do not
remove the bottom bush from the tube unless
it is to be renewed.
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7.16 Check the fork tube for runout using V-
blocks and a dial gauge
7.11 Prise out the retaining clip using a
flat-bladed screwdriver
14 Tip the damper rod seat out of the slider,
noting which way up it fits.
Inspection
15 Clean all parts in solvent and blow them dry
with compressed air, if available. Check the fork
tube for score marks, scratches, flaking of the
chrome finish and excessive or abnormal wear.
Look for dents in the tube and renew the tube in
both forks if any are found. Check the fork seal
seat for nicks, gouges and scratches. If damage
is evident, leaks will occur. Also check the oil seal
washer for damage or distortion and renew it if
necessary.
16 Check the fork tube for runout (bending)
using V-blocks and a dial gauge, or have it done
by a dealer (see illustration). Yamaha do not
specify a runout limit, but if the tube is bent it
should be renewed.
17 Check the spring for cracks and other
damage. Measure the spring free length and
compare the measurement to the specifications
at the beginning of the Chapter. If it is defective
or sagged below the service limit, renew the
springs in both forks. Never renew only one
spring. Also check the rebound spring on the
damper.
18 Examine the working surfaces of the two
bushes; if worn or scuffed they must be renewed.
To remove the bottom bush from the fork tube,
prise it apart at the slit using a flat-bladed
screwdriver and slide it off (see illustration).
Make sure the new one seats properly.
7.18 Prise off the bottom bush using a flat-
bladed screwdriver
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