Sorry to bring up a problem thats been discussed a couple of times in the last 15 years but I wonder if anyone has developed a low tech solution.

I used a 3 legged puller to slide my clutch housing off the output shaft. Unfortunately, the point of the puller has driven the brass centre of the shaft about 8mm down the shaft towards the bike front.

From what I’ve read this brass piece is the ‘pilot bearing bush’.

1) is there actually a ‘pilot bearing’ or just this bush?

2) I gather that the bevelled end of the clutch release rod must ride in the hole at the centre of the bush?

3) Number 2 being the case, I guess I need to get the bush out and replaced.

Previous solutions included tapping and extracting the bush. Anyone think I could achieve the same using a left hand drill?

I think the shaft has oil holes so the presence of brass swarf doesn’t sound like a great plan with either solution.

Some of this info is a bit unclear due the the number of design changes that occurred with the shaft 85/86.

Even though the tap solution has apparently worked I applied quite some pressure to move the bush down the shaft before I worked out that something must be wrong. Not convinced that tapping a thread would allow the bush to be pulled with a screw short of using a slide hammer (any thoughts)?

And if you can get it out that way, how would you secure the replacement ((heat)?

So far I have been unable to locate a source for a replacement bush.

Tapping and machining are way out of my skill set, which means I have to build a stand for the bike to get the sump off and the shaft out and take it somewhere or source a used shaft
Given that the bike is already stripped from the clutch backwards I am hoping for a low tech fix that minimises the chance of more cock ups.

Cheers, Stu

PS a thin walled socket that matched the shaft diameter with the puller point inserted in the 3/8 square socket hole allowed me to get the housing off without further damage.

tinyspuds wrote:So far I have been unable to locate a source for a replacement bush.

There is one depicted in MAX BMW's fiche with a price on its head so that's a hopeful sign but it should be easy enough to machine. This is the part number. 1211461539 You'll know more when you extract the remains.

Thanks Laitch.

Max don’t have any but I have plenty of other bits to clean or update while I wait for someone to suggest ways to minimise ‘the remains’ .

But atm it looks like I’ll be using my Left handed drill bits.

Cheers, Stu

I thought anyone planning on replacing the output shaft rear seal might appreciate a picture of what to expect (and avoid).


The blue circle shows the threaded end of the output shaft from which you have just removed the ‘once only’ 30mm nut, the stepped thrust washer and the cast ali clutch housing. This is where to fit the open end of a thin walled socket. For my smallest puller, the point but not the thread of the adjusting bolt sat nicely in the 3/8” square socket hole. My socket ended up pretty tight against the hole in the clutch housing as I drew it out and I had to use a larger socket to drive the housing back down the shaft to free it and the o ring.

The red arrow shows the pilot bearing bush depressed about 8mm by the puller point before I realised.

Laitch wrote:

tinyspuds wrote:So far I have been unable to locate a source for a replacement bush.

There is one depicted in MAX BMW's fiche with a price on its head so that's a hopeful sign but it should be easy enough to machine. This is the part number. 1211461539 You'll know more when you extract the remains.

The above PN is slightly transposed and missing a 1  search  11211461539

http://shop.maxbmw.com/fiche/PartsSearch.aspx?&searchtype=undefined&parts=11211461539

Good luck with moto

Hi,

Do I understand this correctly that the pilot bushing is just pushed in too far? Is there any gap at the bottom of the bushing and the bottom of the hole? If there is a gap, use a puller made for pulling these bushings. You can either just pull the current one out a bit or totally for replacement.

I just did this a few weeks ago on an old Ford generator. A tool set like below works great. We have a store chain called Harbor freight, Chinese tools mostly, that are reasonable and good for the home mechanic and where I bought my puller set.

https://www.amazon.com/ATP-Bearing-Puller-Remover-Extractor/dp/B075YRHWCM/ref=asc_df_B075YRHWCM/?tag=hyprod-20&linkCode=df0&hvadid=309811990469&hvpos=1o3&hvnetw=g&hvrand=1582070490188208064&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9002737&hvtargid=aud-801738734305:pla-624679758447&psc=1

Glenn

Thanks Volador, thanks Glenn I will definitely have a look at that puller. Unfortunately too late now for this job, I tapped the bush so had to take it out. But your solution would have been much easier as I may have to import a new one from the US.

Ahh had a look now Glenn, I have a similar set that I use on wheel and swing arm bearings etc. Unfortunately the hole in the centre of the bush is only 6mm (same as the clutch release rod it carries) so I would have been tapping anyway.

You could have also packed the hole with grease and then drive, I.e. hammer a smooth shaft close to the bushing ID into the hole. The grease will push the bushing out.

In the end I tapped the bush, threaded a bolt through and used a slide hammer to extract. So, pretty much as previously recommended herein .

I’ve read and seen a number of approaches using packed grease or bread pulp being pounded through the bush hole, but wasn’t entirely happy about the transfer of forces through to the bearing.

As I couldn’t locate one in the UK I sourced a new bush from Germany (shop@leebmann24.de very good service and delivery) which is now installed. There was availability in the US from Max parts but the postage time and cost didn’t really work compared to the EU.

Thanks all as always.

Stu

Now onwards to what appears to be some light thread damage to the output shaft (can’t thread the nut back on by hand and don’t want to force anything so critical) and the swing arm bearings which have come out ok but left their outer races rammed into their seats (I suspect that the gorilla who red loctited the pivot bolt carried the practice through to the bearings) 

Arc weld a thick ring round the bearing races and let them cool. The races will then drop out, literally. It's safe to do with an ally swingarm as long as you don't hang about. I used to remove small-block Guzzi swingarm bearings in this fashion and they're in a cast ally swingarm too.

Had the same experience... can the bush be left further in the shaft or does it need to be flush?

Refer to the link below specifically post 54 & 55, should answer your question

https://www.k100-forum.com/t7249p50-another-85-k100-followed-me-home

thanks for that reference Packo.. it looks like he had only moved his a few mm, ours is probably 10mm or so.. will attempt to hydraulic it out..