Fork cap stuck??

knobs · Nov 4, 2016

Hello
1991 Non ABS st1100, drain holes in bottom of forks.
Removed 10mm bolts , drained oil then, sitting on bike" removed left fork cap
Right fork cap unscrewed but will not come off
It looks different from the left which has thread to the top and a rubber washer.
The stuck one has rubber washer then no visible threads. Unscrewed about 1/4" or 6mm then turned and I get a jump, or click each revolution
Has a 17mm Allen socket

Any Ideas, Help?
Thank you

dwalby · Nov 5, 2016

knobs said:
Hello
1991 Non ABS st1100, drain holes in bottom of forks.
Removed 10mm bolts , drained oil then, sitting on bike" removed left fork cap
Right fork cap unscrewed but will not come off
It looks different from the left which has thread to the top and a rubber washer.
The stuck one has rubber washer then no visible threads. Unscrewed about 1/4" or 6mm then turned and I get a jump, or click each revolution
Has a 17mm Allen socket

Any Ideas, Help?
Thank you

the cap is threaded onto an internal damper rod. You need to slide the fork tube down to expose the threads on the top of the damper rod (fork removed from bike). Hold the 14mm nut on the damper rod with an open end wrench while spinning the fork cap with a 17mm hex driver.

TerryS · Nov 5, 2016

Or, if you have the left cap off still and the front of the bike supported (eg jack under the engine) you just need to lift the front wheel (slide a plank under, then lift) to compress the fork which will push the fork cap up out of the fork tube so you can access the locknut. The locknut bears on a cupped washer on a flat washer on the spacer tube on another washer and then on the spring. There is a fair bit of preload on the spring which means when you reassemble the fork cap on the damper rod, you need to compress the spring to get the locknut in place. That might be easier to do with the fork off the bike.

knobs · Nov 5, 2016

TerryS said:
Or, if you have the left cap off still and the front of the bike supported (eg jack under the engine) you just need to lift the front wheel (slide a plank under, then lift) to compress the fork which will push the fork cap up out of the fork tube so you can access the locknut. The locknut bears on a cupped washer on a flat washer on the spacer tube on another washer and then on the spring. There is a fair bit of preload on the spring which means when you reassemble the fork cap on the damper rod, you need to compress the spring to get the locknut in place. That might be easier to do with the fork off the bike.

than kyou so much for your insight . found that the washer under 14mm locknut is a slide off type. So there is a gap that I used to pour new oil in without removing the or. Cheers.

dwalby · Nov 5, 2016

It is possible to dribble the oil in through the gap in the washer, with the forks on the bike, glad you were able to get the job finished.

Its an easier job with the forks off the bike, both flushing out the old oil, and putting the new oil in. I generally do this maintenance when I'm changing the front tire, so removing the forks only takes a few more minutes.

Fork cap stuck??

knobs

dwalby

TerryS

knobs

dwalby