Death Noises of a K75s

[mgalie]

Terrible happenings. In the middle of a ride yesterday after waiting for a green light, I release the clutch, give some gas, and the bike crawls forward with an awful noise; a noise of gears grinding.

I am perplexed and want to cry, but I keep kewl and remember a few hundred miles ago I installed a new alternator. According to Eilenberger's Law (which one?) I should check this. I do so, and all looks well.

I rock the bike back and forth to try and locate the source of the noise, and it appears to be coming from the Final Drive. I have apocalyptic visions of spline failure, but have my doubts about that, as they were lubed a mere 3000 miles ago with the prescribed Moly 60. Here are pictures of them, though I don't know how helpful they are.

http://photo.xanga.com/lordpoopypants


Then I have an epiphany; the bike was rolling (and grinding) while in gear! DUH. It also grates with the clutch engaged, but not when in neutral.

What think ye, ye masters of the Motorrad? Clutch splines? Some horrible malfunction inside the transmission?

I have taken the transmission off for a clutch spline lube before (this was done last with the FD lube job: i.e. 3000 mi.), but that's about as far as my mechanical comfort zone reaches. Digging inside the tranny is not something I'm really sure I want to do. I hope to dismount it later tonight, and report back then. But for now, I offer this for greater minds than mine to ponder.

Thanks in advance,
Michael

Oh, I forgot, about an ounce of oil came out of the monolever after the FD was removed. That just ain't right, right?

[Voni]

Clutch splines.

Voni

[DarkCloud]

Put that rascal on the centerstand, then rotate the rear wheel by hand in gear and out of gear. Listen for noises.

JON

[Gilly]

Maybe I am misunderstanding your description, but what I am getting out of it is that it's the driveshaft splines.
Gilly

[Burnszilla]

If it's the drive shaft, send it to www.brunos.us to get fixed.

[mgalie]

It's too dark in the garage right now to really see(and somehow there's no flashlight to be found), but I think Voni got it, unfortunately. I got the tranny off, and I'll take a look at it in the morning.

Does Brunos do clutch splines as well? Any other recommendations? Maybe someone in the western Mass/New England area?

[deilenberger]

Michael,

Clutch splines.

How many miles on the bike?

What lube was last used on them and when?

The reason I'm asking - I suspect the bike has some multiple of 16-18k miles on it? That's the usual failure mileage for the splines when there is an alignment problem. Just fixing the splines doesn't fix the underlying problem with the transmission to engine alignment.

As far as getting the transmission repaired - Tom Cutter in PA (right outside Trenton NJ) has a great reputation (RubberChicken Racing Garage). I don't believe Bruno does clutch splines (could be mistaken, but think I would have heard if he did.) The question is - rebuild or replace the transmission? You can frequently find good used K bike transmissions for less $$ than rebuilding your own will cost (if done by someone besides yourself.)

To fix the alignment problem is a bit more work. The usual fix - that works in about 90% of the cases I know of is to replace the intermediate housing (AKA-bell-housing). Theory being the housing is bent somehow causing the misalignment. In some instances - the misalignment was apparently not due to a bent housing, but to a too-thick application of sealant on the engine/housing joint, and someone allowing it to dry a bit before fastening the two together, causing a wedge of sealant (which then misaligns the housing.)

More info is needed, but I'm fairly certain you're looking at a minimum of a new clutch disk and a new transmission input shaft..

Bummer..

[mgalie]

According to the odometer, total mileage is 33,250. And I think that's pretty accurate.

I used Hondamoly60, 3000 miles ago in January.

Interesting idea about the housing being misaligned. I did the spline lube meself, but did not use any sealant. Mebe I misaligned it. Quite possible actually. Makes me feel like a just shot myself in the foot with a $1000 bullet.


Thanks,
Michael

[deilenberger]

According to the odometer, total mileage is 33,250. And I think that's pretty accurate.
And you're the 2nd owner? 2 x 16k=32,000 - awfully close.

I used Hondamoly60, 3000 miles ago in January.

Interesting idea about the housing being misaligned. I did the spline lube meself, but did not use any sealant. Mebe I misaligned it. Quite possible actually. Makes me feel like a just shot myself in the foot with a $1000 bullet.


Thanks,
Michael
No sealant between the housing and the transmission. The sealant is used between the housing and the engine block (to keep the oil inside where it belongs.) Don't blame yourself.. I'm willing to bet 1 beer :drink :

1 - It's a used bike, and it had more than 16k miles on it when you bought it
2 - This happened to it the first time at around 16k miles, and only the disk and input shaft were replaced - treating the symptoms, not the cause
3 - If you fix it without addressing the cause - it will happen again at around 49k miles - even using Honda Moly60.

Some good photos of the transmission input shaft will tell the story. The wear pattern from the misalignment is fairly distinctive. Need in-focus shots of the shaft from various angles - like the ones you did (excellent shots and excellent condition) of the driveshaft splines. At least the driveshaft is in great shape.. It looks as good as I've seen.

[mgalie]

And you're the 2nd owner? 2 x 16k=32,000 - awfully close.



Second owner? I think maybe more like 4th. That's why I got it so cheap.

In the service records there is no mention of any repairs, other than normal consumable stuff, though.



Some good photos of the transmission input shaft will tell the story. The wear pattern from the misalignment is fairly distinctive.


Hope these are helpfull. The clutch plate splines are hardly even there. And the back of the input splines are worn. Is that the pattern?

http://photo.xanga.com/lordpoopypants/albums/e3c210362f0c31





At least the driveshaft is in great shape.. It looks as good as I've seen.

Well that's one positive thing, at least.

[deilenberger]

Second owner? I think maybe more like 4th. That's why I got it so cheap.

In the service records there is no mention of any repairs, other than normal consumable stuff, though.
If you were selling a bike with this sort of failure.. what are the chances you'd be passing those records along with it?

Hope these are helpfull. The clutch plate splines are hardly even there. And the back of the input splines are worn. Is that the pattern?

http://photo.xanga.com/lordpoopypants/albums/e3c210362f0c31Pretty much the pattern. Be easier to see if they were in focus and if you cleaned the splines.. but they're shot and there is a misalignment.

The part you need is the BIG part - without a number in:
http://www.realoem.com/bmw/showparts.do?model=0573&mospid=47906&btnr=11_1782&hg=11&fg=10

The same part is used on K100's - so perhaps we can dig up a PN.. nope, no luck. If the part is still available - showing that image to a parts guy at a dealer might turn it up.

As you can imagine - there is quite a bit of disassembly and reassembly required to replace the intermediate housing.

Well that's one positive thing, at least.

[mgalie]

Found the PN: 11 14 1 461 588

http://www.webparts.com/cycles/ficheframeset.cfm?tablename=K75S


So that has to be replaced, the clutch assembly replaced, and have the gearbox opened up? I think the parts themselves will total nearly the cost of the bike!

[deilenberger]

Found the PN: 11 14 1 461 588

http://www.webparts.com/cycles/ficheframeset.cfm?tablename=K75S


So that has to be replaced, the clutch assembly replaced, and have the gearbox opened up? I think the parts themselves will total nearly the cost of the bike!To really fix it? Yeah. Lots of shops would just do the clutch disk and the input shaft - and let it happen again to another owner down the road. There have been a few we were able to document that had it fail 3-4 times before it was actually "fixed" (new intermediate housing.)

BTW - link isn't working. That's Hammersley's site I believe - have to try it again later..

[Gilly]

I thought the lack of lube causes this. So WHAT is the root cause for this again??? I have 90K on mine, I assume my bike wouldn't be a candidate for a failure like this, as long as all is lubed as it should be?? Yikes!:bolt
Gilly

[deilenberger]

I thought the lack of lube causes this. So WHAT is the root cause for this again??? I have 90K on mine, I assume my bike wouldn't be a candidate for a failure like this, as long as all is lubed as it should be?? Yikes!:bolt
GillyWhile lack of lube is a bad thing - it won't cause the sort of failure seen here. The failure here - at low miles - is caused by misalignment (read above - hopefully I explained it) between the transmission and the engine output shaft. The misalignment causes a tilting motion on the disk with resulting wear on the splines at the center of the disk.

If you have 90,000 miles on yours - I can assure you - you have no alignment problems, and with reasonable lubrication (say every 30-40,000 miles with Moly60) - the splines will probably outlast the rest of the bike (Paul Glaves had > 300k on his clutch splines when his K75 was taken out by a car..)

[mgalie]

So must it be a "new" intermediate housing, or can it be a "new to me" one? Maybe a silly question.

[deilenberger]

So must it be a "new" intermediate housing, or can it be a "new to me" one? Maybe a silly question.New to you - off a bike which hasn't worn the splines should be fine. Also be nice since it would come with the gears/bearings already pressed in..

[Gilly]

Thanks Don. You would think by now I would have heard of the misalignment problem. Appreciate the info.
Gilly