The Marston Sunbeam Club & Register Forum

General Category => Technical Discussion Forum => Topic started by: Thomas on July 01, 2019, 05:57:16 PM

Title: Dismantling the steering friction discs
Post by: Thomas on July 01, 2019, 05:57:16 PM
Hi all!

The friction discs of my steering damper are full of grease and I have no idea where this grease is coming from. I want to clean them but dismantling is a mystery (see the two respective pictures). After dismantling the adjuster at the top with its long axis the locker at the discs does not go loose (see arrow). Strange! Slightly tapping with the damper wheel from the top doesn't help. How do I get the lower counter part off?

In "The Book of the Sunbeam" I find "If the damper needs to be dismantled at any time for the renewal of the friction disks, bear in mind that the bottom back fork bearing pin must be removed, as this passes through the steering damper body".
But what is the "bottom back fork bearing pin"?

Cheers, Thomas
Title: Re: Dismantling the steering friction discs
Post by: AndyB on July 01, 2019, 08:50:11 PM
Quote from: Thomas on July 01, 2019, 05:57:16 PM

But what is the "bottom back fork bearing pin"?

Cheers, Thomas

Hi Thomas,
As it happens I have my forks apart and was able to take the picture attached.
As you will see the lower rear fork pivot shaft passes through the steering damper, so this is the 'pin' which you will need to pull out far enough to release the damper, once you have completely unscrewed the damper shaft from it.
Hope this makes sense!
AndyB
Title: Re: Dismantling the steering friction discs
Post by: Thomas on July 01, 2019, 09:03:46 PM
Thanks a lot, Andy! That was the information I was looking for. Tricky business but easy if you know what's going on. Did you have any problems when pulling out the pin? I ask because I presume that there are bronce bushes which can easily be damaged.
Cheers, Thomas
Title: Re: Dismantling the steering friction discs
Post by: AndyB on July 01, 2019, 09:23:54 PM
My forks have just been reconditioned, and I didn't personally dismantle them - I don't think that as standard there would have been any bushes, but who knows what has been done in the last 80 plus years?!
Best regards
AndyB
Title: Re: Dismantling the steering friction discs
Post by: Rennmaschine1930 on July 03, 2019, 11:29:27 PM
The rear fork spindle should essentially slide out - you can tap the end with a drift to get it moving. Remember to remove both links - one end is threaded onto the spindle. Bronze bushes are pretty resilient. This is a great opportunity to look for any wear along the spindle shafts and bushes. Did you recently grease the spindles and the excess is coming thought the steering damper onto the friction discs?