Spline trouble on my oilhead?

[deilenberger]

A bike like a flat twin fires both cylinders together, but that means the engine creates a power pulse only on every fourth rotation.

Ummm...... actually - AFAIK, based on the engine design, the valve opening/closing and a buncha other stuff - the flat twin alternates firing order - one side fires while the other side is exhausting, then it reverses..

Other than that - you are correct in the impulses from the engine having a shock-wearing impact load on the splines.. but the impulses are half the intensity at 4x the frequency. The engine, unless I'm mistaken, actually makes a power pulse on every revolution.

YMMV, but firing both at the same time would make for a HUGE amount of vibration..

 

[fracture]

Yes, clutch splines on Oilheads HAVE to be lubed to survive.

You can't compare the old Airhead against the Oilhead when talking about not having to lube the splines. Actually, the Airhead clutch splines required it just as much as the Oilheads. That you got 153,000 miles on an Airhead without lubing the clutch splines means you just got lucky. But I bet it was wearing anyway.

The Oilhead clutch spline HAS to be lubed moreso because most Oilheads put out more power and torque than most Airheads. Even though some of the clutch parts are nearly exactly the same. The torque loads on the clutch splines of an Oilhead are higher, both from the power the engine develops, and from the higher wieght of the bike the clutch must get moving.

I have lubed the clutch splines on my 94 R1100RS four times in 120,000 miles. I have also repleaced the clutch assembly in my RS. The output splines on the engine look great with no perceptible wear. If you neglect lubing the splines you could damage the engine output splines in addition to the clutch splines. The clutch hub spline should be considered "sacrificial", because if you ever wear out the engine output spline it means the engine has to be torn down to the crankshaft, and the entire crankshaft must be replaced. Can you say big $$$$?

Makes me wonder about the "legendary reliability" of BMW motorcycles. If it is true that some of the oilhead clutch parts are nearly identical to those found on airheads, what does this really say about how these bike are designed and built?

I do not mind periodic maintenance in order to keep a machine in good working order. In the past, components were usually over-built, thus they were understressed. That did not mean that you could neglect maintenance. What it meant, at least to me, is that the component would last a very long time if properly maintained. Now, put the same component on a more powerful machine and can you expect it to last, even if the required maintenance is performed?

Makes me wonder if the bean counters have ordered the engineers to cheapen the product. This happens everywhere so I am not picking on BMW. It is an economic fact in nearly every product today. Other motorcycle brands are also under the same economic pressure.

Nevertheless, I now think twice about selling my airhead. Sure, I would like to have a new , or newer, BMW motorcycle. I would like more power, better brakes, better suspension. But I expect such an expensive machine to hold up. Stories of final drive failures, seals that can't keep oil inside where it belongs, clutch spline failures, etc. have scared me off. Yes, there are BMW oilheads that have gone a long time before a major component failure. But the failure rate seems too high for me. Is this failure rate within statistical averages? I have not done a lot of research on other brands to determine what the problems may be with them because I do not care to ride other brands. I have tried, but always come back to BMW. I like the ergos and the soul of an air cooled boxer twin.

However, it is not an appealing scenario to be stranded 300 miles from the nearest BMW dealership because a part failed way too early. Someday I might take a chance, get a used oilhead or hexhead, and hope for the best.

 

[deilenberger]

Makes me wonder about the "legendary reliability" of BMW motorcycles. If it is true that some of the oilhead clutch parts are nearly identical to those found on airheads, what does this really say about how these bike are designed and built?

While the design is similar - the components are actually quite a bit different, and the ones used on the oilhead (and I'd assume hexhead) are sized differently - I'd assume for greater loads.

I do not mind periodic maintenance in order to keep a machine in good working order. In the past, components were usually over-built, thus they were understressed. That did not mean that you could neglect maintenance. What it meant, at least to me, is that the component would last a very long time if properly maintained. Now, put the same component on a more powerful machine and can you expect it to last, even if the required maintenance is performed?

It's not the SAME component - it is components sharing the same sort of design - there are only so many ways to design a dry clutch.

Makes me wonder if the bean counters have ordered the engineers to cheapen the product. This happens everywhere so I am not picking on BMW. It is an economic fact in nearly every product today. Other motorcycle brands are also under the same economic pressure.

Nevertheless, I now think twice about selling my airhead. Sure, I would like to have a new , or newer, BMW motorcycle. I would like more power, better brakes, better suspension. But I expect such an expensive machine to hold up. Stories of final drive failures, seals that can't keep oil inside where it belongs, clutch spline failures, etc. have scared me off. Yes, there are BMW oilheads that have gone a long time before a major component failure. But the failure rate seems too high for me. Is this failure rate within statistical averages?

I have no idea - but lets consider your airhead. I've owned one. I've worked on other people's. I have friends who own shops that support themselves on repairing airheads...

Alternator failures - pretty much a given on the airhead. Rear-wheel-drive splines - another given unless you're religious keeping those splines lubed - and even if you do - the rivets holding the hub to the wheel tend to fail. Transmission failures due to the lever return spring snapping - common on some years. Transmission input shaft failure due to the missing snap-ring - common on some year airheads. I could easily go on..

You won't hear much about those failures here - 'cause this is the oilhead forum.

Bet a bit of time over on the airhead forum will turn up "common failures." There are no perfect machines. All machines have some flaw in them someplace - even such highly engineered and cost-no-object machines like the space shuttle.

I have not done a lot of research on other brands to determine what the problems may be with them because I do not care to ride other brands. I have tried, but always come back to BMW. I like the ergos and the soul of an air cooled boxer twin.

It sounds as if you're talking yourself into staying loyal to your airhead. Not a problem.. but not the right forum for it. The people in this forum have moved past the airhead and into a more modern bike - for lots of reasons.. I doubt very much if many are considering going back to an airhead.

However, it is not an appealing scenario to be stranded 300 miles from the nearest BMW dealership because a part failed way too early. Someday I might take a chance, get a used oilhead or hexhead, and hope for the best.

Then I hope you don't have an alternator failure in the middle of Siberia - which Bob Higdon did have - and that convinced him it was time to move on from his beloved airheads. Check how many dealerships carry the airhead alternator rotor in stock.. the chance of getting stuck even in the dealership parking lot waiting for a part for your airhead is probably much higher than getting stuck there if you'd been riding a more modern bike.

There is nothing wrong with loving your airhead and staying loyal to it - but I don't understand the purpose of posting the love here in the oilhead forum..

YMMV..

 

[fracture]

Since I am considering a new bike I thought I would do some research. That is why I look at the oilhead and hexhead forums even though I have an airhead.

Maybe I have been lucky with the old bike. Only a bad rear shock, fork seals, starter, and usual wear and tear items in 40,000 miles. I know the bike has weaknesses and I will just have to live with that. Parts will be harder to get and finding experienced mechanics who are still willing to work on them will be a problem.

In the past, I never did any research on bikes before I bought them so I know I took a chance on my current ride without knowing any of the history of failure prone areas.

Now that more info is readily available I make use of it. It is nice to find people willing to share information. It can help with decisions.

I am not in love with the old bike. It is what it is, I have tolerated its weaknesses, and I am ready for something new. But I want to know what I am getting into. These forums provide a lot of information. If I know where the weak spots are on the new bikes maybe I can better prepare for them.

But, I do not want to trade one set of problems for another. I have reservations. Reservations that may or may not be alleviated by obtaining the information that is found in these forums.

When a previous post mentioned that the need for oilhead clutch spline lube maintenance is as necessary as it is on an airhead it provided a bit of information I did not have before. It would have been nice to see less maintenance required in this area, but I suppose in this day and age more complexity means even more maintenance.

I only mentioned my airhead as a way of showing that I am a fairly loyal (up to a point) BMW rider and would like to move up. I certainly did not intend to "contaminate" (lol) the oilhead forum by mentioning airheads.

 

[deilenberger]

In the past, I never did any research on bikes before I bought them so I know I took a chance on my current ride without knowing any of the history of failure prone areas.

Good idea actually - but you should do this with the realization that most people with perfectly running and troublefree bikes don't post that. I just took a look-see at the airhead tech forum, and as I sort of expected, more than 50% of the postings were on problems people were experiencing.

The forum is a great way to find out what MIGHT go wrong - but unless it's obviously endemic (happens to EVERY bike) - you have to balance the failure reports with the fact that most people don't report non-failures.

When a previous post mentioned that the need for oilhead clutch spline lube maintenance is as necessary as it is on an airhead it provided a bit of information I did not have before. It would have been nice to see less maintenance required in this area, but I suppose in this day and age more complexity means even more maintenance.

Don't take everything you see posted in a forum as gospel. Even what I write. If Paul Glaves said "you gotta lube the splines every XX,XXX miles - then it's Gospel to me - Voni has about 600,000 miles on oilheads. And Paul did post the number he uses someplace not long ago - I believe it's up around every 50,000 miles, but my memory could be wrong. To me - that's not an onerous task to perform at 50,000 mile intervals.

I only mentioned my airhead as a way of showing that I am a fairly loyal (up to a point) BMW rider and would like to move up. I certainly did not intend to "contaminate" (lol) the oilhead forum by mentioning airheads.

It wasn't comtamination - I just wondered why.. and you have a good reason. Don't be scared off oilheads by the failure reports you see - they are actually rather rare in my experience.

Best,

 

[ARM74]

Wow! I've created quite a discussion with my original "spline" posting. I appreciate everyone's input. I've been given a lot of info. to absorbe. Here is what it comes to:

I think i'll begin with the clutch cable adjustment/replacement (start with the easier stuff first, right?). From there, i'll need to look into spline lubing. Now, is that something that can be performed in my driveway, or do I need to contact my dealer? I'm reasonably adept at servicing my vehicle(s) and would prefer to do it myself, probably with the aid of a good service manual.

I spoke with a dealer about this 2 months ago (after reading the April issue of BMWON where P. Glaves mentions spline failures) and the reply was "We don't lube splines on oilheads." In fact, he assured me that he has only seen spline failure on an oilhead ONCE and that was due to a trans. housing misallignment. He suggested that I put a heavier oil in my transmission (Lucas Oil) which could fix the problem. It didn't.

I'm inclined to believe what I've read here recently, so I'll get the splines taken care of one way or another. I'm just concerned that a dealer would be so quick to disregard my situation when it sounds like a "common" (for lack of a better term) failure.

Thanks to everyone, again, for the interest in my issue and all the information.

Ciao!