Fork stanchion lower guide bush

[st1cks]

Hi I am working on the forks of my 2000 1150gs and replacing all seals and bushes to sort out a rather loose front end.
The stanchions were well scored and worn so needed to be replaced. New yoke bushes are done.
The upper stanchion (fork leg) bushes are out with signs of wear so I assume the lower bushes, below the plastic sliders will be no better, but hard to see.

So far I've been unable to remove the lower fork stanchion guide bushes, despite attempting to push and pull with what I have to hand.
Can anyone point me to a good safe removal method for these lower bushes ?
Thanks!

 

[Hay Ewe]

If you do get them out, how are you going to get them back in?

I am currently doing a service on a set of 1100GS fork legs and reassembled all on but the inner sliding tube only goes so far and then stops. They were ok when i dissassembled them.
I think the reason is that the top bush is not installed squarely. And so by the time that the inner sliding tube gets to the lower support, there is too much offset.

A) i know the 1100 and 1150 forks are different, i checked the IPC (Illustrated Parts Cattledog) (i use the MaxBMW website)

B) if you do get the lower bush out, you have to get it back in and square, other wise you will have problems with the alignment between the lower and upper bush.

I think for the 1150 series and for the 1100S, the bottom of the fork leg tube actually unscrews.
I read about this on the Boxertrix forum, in the thread.

Cracked FR Fork leg ??? !!! - www.boxertrix.com

I dont think there will be as much or it any wear on the bottom bushes because they are constantly in oil and the angular deflection is much less, compared to the top bushes.

I wouldnt worry about them.
Remember phrase "If it isnt broken dont fix it".

 

[st1cks]

Thanks for the reply. I made up an extractor after an overnight head-scratch and now see, it turns out to be similar to a solution others have tried.

I've attached some pics.
Filed two sides off a large washer, sized to be just smaller than the bush and to clear the tighter lower leg dimension. The washer slips through and then pivots under the bush.
After making sure everything is correctly centred, wind it up the threaded rod, I added a cut down aerosol cap to protect the top of the fork leg from the top washer and keep the rod centred. The filed washer is recoverable if something goes wrong, just loosen and turn it upside down.

I've drifted in the new lower bushes already, gently, with a large washer sized to fit just within the leg to engage the bush and then drifted it with a socket on a couple of extensions that I could tap with a rubber hammer.
I measured the distance of the seated bush before removal and am fairly sure they are snug down.

Turns out there was a lot of wear on one of the lowers, that stanchion was quite scratched and well worn through the chrome at the top and bottom with a lot of grey slurry, so replacement was fairly essential.

After your comments on alignment, I'm going to try and slide the fork stanchion into the lower bearing and make sure it centres at the top of the leg, before I fit the sliders, top bush, washer and seals.
Hopefully everything will line up.

 

[Hay Ewe]

Mmmm, clever with that washer.
I worked my fork tubes again yesterday and now think they are bent, which matches the known history of this bike (i bought it for a project).
Am going to run the inners across some V blocks and measure the run out.
Based on those findings will tell me if its the bushes or not.
(The bike last ran approx 2000 so when i dissassembled the forks they were stiff anyway and i didnt notice any thing ab normal).

 

[st1cks]

The bushes and everything seemed to line up fine and nice smooth action on my forks now that they're fully assembled.

With new bushes, it might well be something isn't straight with your fork legs or stanchions.
Might it be easier to go for a replacement leg? I hadn't heard of splitting the tops and bottoms before.
Hope you get it sorted.

 

[Hay Ewe]

THis morning we straightend the inners in the press at work, they are straight now, but still dont fit properly.
Did put a straight edge along the outers and they are bent as well.
May be able to straighten the outers but expected they will break and i need the front end assembled so that i can meve the whole thing around.
I do know where there is an 1100GS for parts though, but there are other options.