11-10-2012, 04:45 PM
FORK OIL SEAL and SPRING REPLACEMENT
fork_spring-seal_replacement_1988_on.pdf (Size: 994.45 KB / Downloads: 35)
FRONT FORK BASIC COMPONENTS
With someone holding the bike, and before placing it on the centre stand, start by loosening the
domed ‘fork spring stud nuts’ at the bottom of each fork end. The weight of the machine
pressing down on the ‘spring stud’ will help to prevent the stud turning in the alloy fork tubes
while unscrewing this nut. If the stud starts to turn, put more pressure on the forks and tap the
spanner sharply with a hammer, this should be sufficient to free the nut. Occasionally, these
nuts will not come undone and you may have to resort to carefully cutting the nut off.
Place the machine on its centre stand and support the front of the engine on a strong box to lift
the front wheel clear of the ground. Disconnect the speedo and brake cables. Unscrew the 4
shouldered nuts and remove the 2 ‘fork spindle clamps’ and remove the wheel. Unscrew the 6
nuts holding the mudguard stays to the alloy fork ends. Pull the stays off the studs, twist and
drop the mudguard out of the forks.
Fit the oil control collar on to the fork spring stud, with taper
facing upwards. Again, a little grease will help to hold it in place
on the spring stud.
The alloy fork tube is now ready to be pushed on to the fork
main tube. The special tool (part ST25112), fork oil seal
expander, will make this job easier and prevent damaging the
seals on the edges of the main tube and castellated valve port.
A useable substitute can be made from a piece of strong
polythene coated in grease, pulling this out as the seals slide
over the end of the main tubes.
Push the fork end up until the fork spring stud protrudes
through the bottom. This simple task can be a tedious and
frustrating business! The drilling in the bottom of the alloy fork
tube is a very tight fit against the thread on the end of the fork
spring stud to help eliminate oil leaks. The tight fit also helps to prevent the stud turning during
assembly and removal. The stud will, therefore, need to be encouraged to pass through the
drilling in the bottom of the alloy fork tube. It can help to lie on the floor, using a torch, to see
exactly where the fork spring stud thread is in relation to the hole in the alloy fork tube. It will
also help if the stud is guided into the hole by means of a screwdriver from underneath. When
sufficient thread is showing, place the nut and washer on the thread and tighten. You may need
to put some weight on the forks in the same way as when you disassembled them. If the stud
seems to turn before the nut is tight, it would be worth removing the stud again and smearing
some loctite on the area of the stud which is located in the alloy tube.
Remove the slotted fork plug screws from the top of the fork legs and refill with 200ml of oil in
each. Refit the mudguard. Refit the front wheel ensuring that the brake plate anchor lug is fully
located in to the brake plate. Replace the 4 spindle clamp nuts; do not over-tighten, or you will
break the alloy clamps. (The correct torque is 9 lb-ft [1.30 Kg-m]). Reconnect the speedo cable
and reconnect and adjust the brake cable. Check the brake and fork action before going back
on the road.