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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: brickme on July 16, 2012, 01:43:51 AM

Title: Replacing Fork Spring Retainers, '95 K1100LT
Post by: brickme on July 16, 2012, 01:43:51 AM
Hello Motobrickers,

Recently became the owner of this fine machine and am catching up on some of the deferred maintenance.  Changing out the fork oil and read up on the procedure on this website, Clymer's and the BMW service manual before starting.  A previous "mechanic" overtightened the fill plugs, stripping out the spring retainers (I had that sickening feeling when the fill plugs were too loose and got tighter as they came out.  Can't get them much more than hand tight going back in).  So I'm wondering what I am up against to replace the retainers.  Is there much spring pressure on them with no weight on the front wheel?  Is it easy to just loosen the old ones to remove them and push down on the new ones while starting the threads?

Thanks in advance for any advice or tips!
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: Inge K. on July 16, 2012, 06:06:44 AM
Welcome Brickme!

This (http://www.largiader.com/tech/k11forks/) might answer your question.

Inge K.
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: brickme on July 16, 2012, 01:37:52 PM
Thanks for the link Inge.  The photo and description help show how it all fits together.  The question I have is when it is all assembled, with no weight on the front wheel, is the spring being held under significant preload by the spring retainer(or "top plug" as it is referred to in the linked page)?  I want to make sure when the retainer is removed, parts don't go flying and I have to trailer the bike to a shop to reassemble everything.  If this turns out to be beyond my capability it would be better to ride it in for the repair.
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: Inge K. on July 16, 2012, 02:08:56 PM
The "stop disc" is the spring retainer, top plug sits above this.

Inge K.
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: mystic red on July 16, 2012, 02:09:18 PM
It's still under pressure and it helps to have an extra set of hands when reassembling. But it's not rocket science. You can do it.
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: Scott_ on July 16, 2012, 07:14:37 PM
It's still under pressure..........

That's news to me. I replaced on of mine on the '97, just unscrewed the cap, lubed the o-ring and put the new one back on..... No spring pressure what so ever...
I was expecting the possibility of some spring pressure, but there was none.
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: Motorandy123 on July 16, 2012, 08:29:13 PM
Generally speaking the amount of pressure is equal to the amount of preload. I've never had a k1100
apart but some that I have had were 1/2" of preload. At 0.74 kg/mm and about 13mm you have 9.6 kg's
which equals about 21 pounds of force. Should be fairly easy to push it on. I use a gear puller to push
against the spring, it leaves my hands free to fiddle with the snap ring and so forth.
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: Rick G on July 16, 2012, 10:29:10 PM
I used a knife edge bearing puller with two long bits of threaded rod to extend it out to do mine a while ago.  I also made two 1/2in longer spacers to give more preload as I am a heavy guy, 300lb.
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: frankenduck on July 16, 2012, 10:39:01 PM
If you're looking for the fork caps with good threads then drop me a line.  I recently disassembled a pair of badly pitted forks and I have some good fork caps.
Title: Re: Replacing Fork Spring Retainers, '95 K1100LT
Post by: brickme on July 17, 2012, 12:09:21 AM
If you're looking for the fork caps with good threads then drop me a line.  I recently disassembled a pair of badly pitted forks and I have some good fork caps.

Duck, Figured my odds of finding used ones with unmolested threads was nearly zero so I already ordered new ones from a dealer!  I will contact you in the future to check on other used parts though.

Scott_, That's good news indeed from someone with the same bike.  Now I'm jazzed about doing the fix.  Just need to buy a 30mm wrench....

Thanks to everyone who responded with suggestions!