Ohlins Fork seal replacement
(you know you'll have to do it someday...)
Step 1. Get the Ohlins manual; it's available at the Ohlins web site, and is a
terrific knowledge base to start from. I found some of the details to be
pretty sketchy, so I put this page together.
First, get the sticks off. Pull off the wiper (you do this to clean it
all the time anyway, right? Right?) Get the wire clip out so the seals
and bushings can come out. This is all in the manual, and is easy.
Pull all the goodies off the top, again per the manual. The 24mm nut
(use a 16mm on the damping rod to loosen it), the fork cap, the spacer
thingy, the white plastic shim, and the fork spring. On the left you see the
wire clip that holds the inner seal in.
Use the two halves of the fork tube to slide hammer things apart.
(it's like topping out really hard a whole bunch of times) You should
end up with this.
Making a bushing/seal driver involves cutting a piece of 1 1/2" PVC in half lengthwise.
Left picture: how it looks. Right picture: After heating and pressing to fork tube. I
just held it up to a catalytic heater, but I suppose a heat gun would do the job.
Now make sure you have all the new parts stacked up in the right order. You'll have
to slip the upper bushing off the tube to get the seals and stuff on. It's split, like the
other bushings. No big deal, open it a tiny bit with a small screwdriver and it'll slip
right off. I zip tie the spacer so it's easier to start down the fork tube. You want to
drive one bushing in as far as possible, then start driving the spacer and bushing in,
then finally start the last bushing and drive it in.
On the left, the last bushing driven in properly. Note that it is all the way in, flush with
the fork tube. On the right, you should be able to push the inner seal in this far by
hand, pretty easy. You'll have to use the driver to seat it, though, and be sure that
you are driving the outer edge of the seal, not the lips!!
Seat the wire circlip (it should 'click' into place), seat the wiper back on, and you
are ready to fill with oil. I've found it best to fill the silly thing right to the top, then
stroke the outer tube a few times, then stroke the damping rod until you don't hear
any bubbles in the works. Adjust your oil level, add the goodies to the top (spring,
shim, spacer thingy, fork cap, nut) and you are just about ready to go.
NOTE: Tighten the fork cap ONLY by hand and ONLY until it covers the O-ring
at the top of the damping rod. Otherwise it gets wicked stuck.
And in that case, an Inch and 1/8" combination wrench with a crescent
wrench, backed up by a 16mm, is how you get it loose. You have to
bear down on the big wrench, it'll want to pop out when you put the
torque to the thing!
Finally, if you are lucky like me, the innards DON'T come out as advertised.
This is what I got out. No big, just wiggle the top bushing around
until it starts up the fork tube, then help it slide on out. The spacer will
come out with a pair of needle-nose pliers. The upper bushing, well,
you'll have to 'encourage' it to come out. I used a peice of 3/4" PCV
and a good deal blow hammer.
In the reflection-fest on the left, you can make out the top bushing, which is laying
loosely in the tube. It goes out away from us in this view, and is easy. The upper
bushing is on our side of the top bushing, and is a press fit. It comes out towards
us in the picture.
Removing it looks like the picture on the right. Tap, tap, tap. Change sides each
time you hit it, and make sure you hit it across the split; otherwise you can twist
the bushing in the tube making it really hard to drive out.