2003 R1150RT To lube the spine or not to lube the spline

[PAS]

If there is an alignment problem with the gearbox housing, which does cause spline failure. This clutch disc wont correct it.

[PGlaves]

If there is an alignment problem with the gearbox housing, which does cause spline failure. This clutch disc wont correct it.

True. But misalignment is not the problem this modification addresses. The fact that the shaft only partially sticks into the clutch hub is the issue here. Engaging the entire clutch hub spline has to be better than engaging 80% of that spline.

[Roger 04 RT]

...
Interestingly, he believes those riders like me - who tend not to wind the rpms out in each gear - are more likely to have the spline problem with their bikes than riders who push their machines harder.
...

Interesting video, thanks.

To your point above, riding at high RPMs for any given power output results in a lower torque load than lower RPMs.

For example, 15 HP output at 5200 RPMs takes about 15 lb-ft of engine torque at the transmission input shaft. If you drop to 2600 RPM for that same 15HP the engine has to deliver 30 lb-ft of torque at the input to the transmission. I don't think that's a great reason to keep the bike so wound up but it is the physics of the matter.

As I mentioned above, I've got about one degree of play between the clutch hub and input shaft. Any ideas what the play is on a new hub/shaft?

[NRPETERSEN]

I've got about one degree of play between the clutch hub and input shaft. Any ideas what the play is on a new hub/shaft?

That would be about .008 inch tooth-to-tooth clearance. I'd guess there is maybe .003 tooth clearance (strictly a guess) on a new spline but someone with a spline set could come up with an actual number.

Your spline alignment is presently pretty good obviously. If it was my bike, rather than chance an additional misalignment from dis and re assembly, I'd look into a hypodermic lube of each tooth. It is critical that each surface be lubed yet not get so much in that it would splatter onto the clutch disk. Some experiments with a bent insulin needle and slightly thinned spline lube would be in order first.

Strictly my opinion.

[Roger 04 RT]

That would be about .008 inch tooth-to-tooth clearance. I'd guess there is maybe .003 tooth clearance (strictly a guess) on a new spline but someone with a spline set could come up with an actual number.

Your spline alignment is presently pretty good obviously. If it was my bike, rather than chance an additional misalignment from dis and re assembly, I'd look into a hypodermic lube of each tooth. It is critical that each surface be lubed yet not get so much in that it would splatter onto the clutch disk. Some experiments with a bent insulin needle and slightly thinned spline lube would be in order first.

Strictly my opinion.

The hypodermic lube has been on my radar screen. This is probably an inexperienced question, but how could I create a misalignment by taking it apart and putting it back together. Won't the alignment pins insure that it is assembled in the same alignment?

[bikerfish1100]

That would be about .008 inch tooth-to-tooth clearance. I'd guess there is maybe .003 tooth clearance (strictly a guess) on a new spline but someone with a spline set could come up with an actual number.

Your spline alignment is presently pretty good obviously. If it was my bike, rather than chance an additional misalignment from dis and re assembly, I'd look into a hypodermic lube of each tooth. It is critical that each surface be lubed yet not get so much in that it would splatter onto the clutch disk. Some experiments with a bent insulin needle and slightly thinned spline lube would be in order first.

Strictly my opinion.

the onlyy misalignment that can be created by a disassembly/reassembly process is from failing to align the clutch disc itself (not using a pilot tool). the shaft misalighnment that destroys the shaft and clutch hub is one that exists in the interface between engine block and trans housings. that can not be created nor corrected via bsic mechanical work in this area.
if you were thinnking otherwise.... nevermind.

[MUCHOGUM]

I don't know what Bruno Sax charges for his re-machined clutch plate, but the customer cost at Affordable Beemer Services is $600.00. The labor cost to install is extra. My understanding, which is superficial, is that folks like me who drag up the rear of the convoy tend to stress the transmission/clutch interface more, and thereby exacerbate the damaging effects of any play between the two. Guys who push their machines seem to shift more cleanly with better coordination between engine and transmission speeds. Chris Harris very willing to answer e-mail inquiries. He can be reached at Chris Harris . No, I have no financial relationship with him, except the one associated with paying bills associated with his work.

[NRPETERSEN]

Yes re-alignment should be good if the clutch disk is properly centered before reassembly - or if the clutch is dis engaged as the transmission is pulled up to the engine. My concern is that some are using tape etc on the outside of sockets etc as an initial clutch disk alignment tool, and which allows reassembly. But that isn't good enough.

I'm not even sure in the presence of engine main bearing wear, if an accurate alignment tool is enough.

The clutch housing of the R1XXX bikes is an open section of thin aluminum alloy. Other BMWs don't have the open starter port. I'm speculating that possibly the open section structure makes realignment chancy if there is any assembly shear force between the rotating systems - even with alignment pins.

As a minimum pull (and bungee) the clutch in before pulling up the engine transmission bolts.

The reason I think this way is that BMW has somehow allowed this random problem to go on through many years. I would think that they would be trying to improve the accuracy of the transmission housing setup during manufacture, yet have been unable to really fix it. What could they be overlooking? Maybe, it is the structural rigidity of the raw housing (die?) casting. That's why I hesitate to disassemble what is already working. Again, I have no basis to assume this is fact, just speculation.

[Bobmws]

Yes re-alignment should be good if the clutch disk is properly centered before reassembly - or if the clutch is dis engaged as the transmission is pulled up to the engine. My concern is that some are using tape etc on the outside of sockets etc as an initial clutch disk alignment tool, and which allows reassembly. But that isn't good enough.

I'm not even sure in the presence of engine main bearing wear, if an accurate alignment tool is enough.

The clutch housing of the R1XXX bikes is an open section of thin aluminum alloy. Other BMWs don't have the open starter port. I'm speculating that possibly the open section structure makes realignment chancy if there is any assembly shear force between the rotating systems - even with alignment pins.

As a minimum pull (and bungee) the clutch in before pulling up the engine transmission bolts.

The reason I think this way is that BMW has somehow allowed this random problem to go on through many years. I would think that they would be trying to improve the accuracy of the transmission housing setup during manufacture, yet have been unable to really fix it. What could they be overlooking? Maybe, it is the structural rigidity of the raw housing (die?) casting. That's why I hesitate to disassemble what is already working. Again, I have no basis to assume this is fact, just speculation.

I understand the potential for damage from misaligned cases, but regarding the disc centering tool, what am I missing here? Wouldn't the disc self center the first time the clutch is dis-engaged, especially if dis-engaged while drawing up the bolts?

[rad]

Yes re-alignment should be good if the clutch disk is properly centered before reassembly - or if the clutch is dis engaged as the transmission is pulled up to the engine. My concern is that some are using tape etc on the outside of sockets etc as an initial clutch disk alignment tool, and which allows reassembly. But that isn't good enough.

I'm not even sure in the presence of engine main bearing wear, if an accurate alignment tool is enough.

I must admit IÔÇÖm confused. Are we all talking the same thing here?

I have done the spline lube a few times on three different model Oil Heads. The clutch alignment process for reassembly has nothing to do with the how the trans/engine/clutch align in regards to run out, or out of alignment issues, between the engine and trans when assembled.

Aligning the clutch upon reassembly is nothing more than allowing the output shaft on the trans to find the hole in the clutch plate. This alignment process (no matter what process is used)has absolutely nothing to do with how well the trans and engine on the bike line up or mate together when bolted together; that is a fixed relationship dictated by the manufacturing of the mating surfaces. There is absolutely nothing you can do to change that alignment short of reengineering the mating surfaces or mating dowels.

[NRPETERSEN]

Remember you are trying to align the engine to the transmission within say .002 inch. That would give .004 TIR (DIN specs say .003 for good spline life) that will be dragging the clutch disc across the flywheel every revolution of the engine, fretting the spline. And who says that the engine crankshaft is sitting in the center of its operating axis when it is not rotating? My guess is that it could drop down one or two thousands just by its own weight crushing the rear main oil film.

Furthermore, if the rear crank main bearing is at all loose (it is spec'd at .002 service limit I think) the piston forces will end up hammering the front bearing in the transmission.

Think of the spline as a 1:1 internal-to-external gear set. It is highly loaded even if there is no cyclic variation of tooth load as it rotates and all the teeth carry the torque. But now suppose the two axes don't coincide and it has to operate as a gear (after all it has an involute profile so it can smoothly do that). And mix all this with only an initial assembly lube in a dirty environment.

Why generally do only oilheads have spline problems? I suspect it may be due to the unusually lightweight design of the clutch housing combined with the comparatively large open port for the starter. Airheads (and K bikes ?) don't have the starter port, and have a more distributed piloting scheme.

[NRPETERSEN]

FWIW - My R90/6 did have a spline strip-out about 20 years ago. I rebuilt it without understanding these issues or having this forum.

A year ago I ripped it down again for a spline lube but this time i left it a little loose and let the clutch out & started the engine. With my finger I could feel micro-flexing between the engine and the clutch housing which I tried to eliminate by repeatedly pulling in and letting out the clutch. It didn't work. Each time I let the clutch out, the flexing would restart. So the "better alignment pilot" is not in my R90.

[NRPETERSEN]

Reply to Bob Weis and Rad

I have done the spline lube a few times on three different model Oil Heads. The clutch alignment process for reassembly has nothing to do with the how the trans/engine/clutch align in regards to run out, or out of alignment issues, between the engine and trans when assembled.

Aligning the clutch upon reassembly is nothing more than allowing the output shaft on the trans to find the hole in the clutch plate. This alignment process (no matter what process is used)has absolutely nothing to do with how well the trans and engine on the bike line up or mate together when bolted together; that is a fixed relationship dictated by the manufacturing of the mating surfaces. There is absolutely nothing you can do to change that alignment short of reengineering the mating surfaces or mating dowels.

I agree you've done what you can if you draw the bolts up with the clutch lever pulled in assuming the clutch housing doesn't deflect. My contention is that it may be deflecting otherwise since it is such a light weight design.

[JimMoore]

A couple days ago when I was working on the starter I had a look at the splines. After tie-wrapping the clutch handle to pulled in, I looked for movement between the hub and aplines. At the clutch plate outer edge I had about 1/16 of an inch of free movement before the splines also moved. This calculates to about 1 degree. I'm assuming this is fine.

Can I ride with piece of mind that all is well?

The play is essentially zero on a new clutch and splines. You have a certain amount of wear. People have seen up to 10 mm of play prior to failure so you're not in any imminent danger. I would put it back together and check it every 10K miles.

[happy wanderer]

about 6 or 7 yrs ago there was a guy in Canada (pretty sure it was not Bruno) that did basically the same thing. he had made up some prototypes, and was offering kits for sale for about $1G. never sold well- as stock parts were less than 1/3 of that, and most prospective buyers (he had posted on Pelicanparts.com's ) didn't see themselves replacing the clutch pack 3+ times.
do you know what Bruno's charging?.. i did not see the items on his website.

The guy in Canada was GSAddict but it was a high quality hardened and longer input shaft he was offering, not a clutch disc like Bruno. Reason for high cost was the machining was very precise, the steel specially hardened and the very low volume. I think he was trying to get a group of orders together to reduce cost but folks balked at the price probably not realizing what was involved. There was almost zero profit in it. I've seen the second prototype and it is a thing of beauty and much better than an original shaft that extends properly through all the length of the clutch splines.

It's been in his bike for quite some time now but the test is a very long term project.