Driveline Problem

[dbrick]

2007 model, 33K miles. Maintained per BMW's schedule at Ted Porter's shop.

Leaving Death Valley Sunday morning, I felt a roughness and heard a small noise, like you'd get when traversing closely-spaced tar snakes: brrp brrp brrp brrp etc. No rear wheel play at either 12/6 or 9/3, and no oil seep at the rear end. Ridden downhill, the bike would accept power but made more noise. As we loaded the bike into a pickup truck, we noticed that the rear wheel would rotate backwards only a fraction of a turn, then it would lock; the wheel rotated forward just fine. There's mechanical noises coming from the driveshaft area. Preliminary diagnosis: rear u-joint.

The truck's in my driveway, and the bike will go into the shop Thursday. I'll let you know what develops.

[hankth]

Bummer. how many miles on the bike? hope it's not too spendy.

[Steve H.]

BS. Something is way out of normal.

[dbrick]

BS. Something is way out of normal.

Indeed. That's why it came home on a truck. <g>

[Bob Ain't Stoppin']

U-joint is indeed possible. Also the input bearings on the rear drive can do that. Good luck

[dbrick]

I wondered about the input bearing. I can imagine that if it failed in a certain way, the bits could behave as a sprag, allowing rotation in one direction but not the other.

[Lost Rider]

I seem to remember similar behavior when the u-joint gave way on mine.
You have a lot less miles though, that's the weird part.
Luckily it's an easy and relatively inexpensive fix if you buy a used drive shaft on ebay, the cheapest thing that can fail back there for sure, I hope that's all it is for you.

[dbrick]

I dropped the bike off this morning at the shop. Once the rear drive was removed from the swingarm, the problem was evident:



The u-joint was clearly deceased. There wasn't much surface corrosion on the pieces, and Ted didn’t think the joint had died from moisture. He said the pieces seemed (looked? smelled?) as though the joint had gotten extremely hot before it failed; he described a failure mode where the needle bearings get loose, and the moving bearing beats open the opening in the u-joint trunnion until the trunnion or the crosspiece fractures. This seemed a reasonable explanation of what I saw. As needle bearings live long lives in terrible conditions (open to the elements) in automobile driveshafts, this failure suggests BMW uses bearings bought to a price, not quality.

Fortunately, I’d stopped the bike quickly enough that the swingarm wasn’t significantly damaged; there was only a small abrasion to the lip that retains the rubber bellows:



Ted says they see this failure on Hexheads often enough not to be surprised, and said he doesn’t know if it’s more power, or cheaper bearings, or something else. In any event, this one is not repairable even if parts were available...and they're not. Instead, one must replace the whole driveshaft.

A new driveshaft is about $800. I’ve heard there was a running change in the driveshaft about 2009. Hoping that newer parts might be sturdier, I’ll spring for a new piece instead of looking for a used one.

[peels]

wow. nasty...looks like a shaft out of an old beat up truck.

could be worse though I guess...?

[R12RnHouston]

This has me thinking more than ever about having Bruno upgrade my driveshaft.

[xprof]

Oh David, that's UGLY! Good thing you had the truck as back-up...

[dbrick]

Good thing you had the truck as back-up...

Yup. Cameron's brother Aaron commented on the "graceful recovery." I was amused when the recovery party first showed up: three doctors (two opthalmologists and a GP) in a truck. Quite a "house call!"

[PhilSB]

I once had a grumbling noise from the drive area. To cut a long story short I rode home slowly and had it taken to the dealer. They couldn't find anything wrong and it's work fine ever since . I felt a bit of a wally. Perhaps gravel trapped against the disc? At least it didn't cost me anything.
The dealer has an event showing off the new bikes on Saturday, perhaps the new S1000R might be a nice ride? I haven't ridden my R since October, it's about time I did.

Phil

[R12RnHouston]

Resurrecting this thread. I had my drive-shaft upgraded by Bruno (http://www.brunos.us/) and wanted to show you all the results.



The rebuild with grease inserts and heavy duty u-joints installed with snap rings was $390 plus shipping. About a seven week turnaround.

[deilenberger]

The rebuild with grease inserts and heavy duty u-joints installed with snap rings was $390 plus shipping. About a seven week turnaround.

Looks nice. I assume there wasn't a problem with the shaft before this? Did he do both U joints (front and rear), and is there any fitting on the cross to lube the bearings (?? :grease inserts" ??)

I just did my rear drive oil in anticipation of a little ride I have planned (coast-to-coast-to-coast), and checked my U joint. Looked and felt perfect. I had in the past coated the cross-area where the bearing seals are with some grease in the hopes of keeping moisture (if any got into the housing) out of the bearings. I saw no signs at all of any moisture ever being in the housing or swingarm, but I am very careful to make certain the accordion boot is installed correctly - and sealed - when I move the rear drive back up in position.

I have a spare low mileage driveshaft in the garage, packed and ready to go if I needed it.. so chances are - I won't (Eilenberger's Law of Spares.) Oh - the rear drive oil once again looked perfect. Looked as clear as what I was putting in (the Castrol SAF-XO GL5 stuff in a BMW bottle..)

[R12RnHouston]

The rebuild with grease inserts and heavy duty u-joints installed with snap rings was $390 plus shipping. About a seven week turnaround.

Looks nice. I assume there wasn't a problem with the shaft before this? Did he do both U joints (front and rear), and is there any fitting on the cross to lube the bearings (?? :grease inserts" ??)

I just did my rear drive oil in anticipation of a little ride I have planned (coast-to-coast-to-coast), and checked my U joint. Looked and felt perfect. I had in the past coated the cross-area where the bearing seals are with some grease in the hopes of keeping moisture (if any got into the housing) out of the bearings. I saw no signs at all of any moisture ever being in the housing or swingarm, but I am very careful to make certain the accordion boot is installed correctly - and sealed - when I move the rear drive back up in position.

I have a spare low mileage driveshaft in the garage, packed and ready to go if I needed it.. so chances are - I won't (Eilenberger's Law of Spares.) Oh - the rear drive oil once again looked perfect. Looked as clear as what I was putting in (the Castrol SAF-XO GL5 stuff in a BMW bottle..)

Yep, both u-joints. The dome-shaped screw in the picture is removed, screw in a "zerk" fitting, grease it (three pumps of grease with moly every 10K), and replace the screw. Mine had a lot of corrosion on the rear that I like to blame on the previous owner who apparently didn't notice a defective rear-boot. Bruno confirmed that the rear bearings were a bit "grabby" and might fail (which i noticed myself when I replaced the rubber boots). That was really my motivation.

[deilenberger]

Yep, both u-joints. The dome-shaped screw in the picture is removed, screw in a "zerk" fitting, grease it (three pumps of grease with moly every 10K), and replace the screw. Mine had a lot of corrosion on the rear that I like to blame on the previous owner who apparently didn't notice a defective rear-boot. Bruno confirmed that the rear bearings were a bit "grabby" and might fail (which i noticed myself when I replaced the rubber boots). That was really my motivation.

Is the grease point accessible on the front U-joint? I've never had my front boot off so dunno, but it appears rather tight there.

[R12RnHouston]

Yep, both u-joints. The dome-shaped screw in the picture is removed, screw in a "zerk" fitting, grease it (three pumps of grease with moly every 10K), and replace the screw. Mine had a lot of corrosion on the rear that I like to blame on the previous owner who apparently didn't notice a defective rear-boot. Bruno confirmed that the rear bearings were a bit "grabby" and might fail (which i noticed myself when I replaced the rubber boots). That was really my motivation.

Is the grease point accessible on the front U-joint? I've never had my front boot off so dunno, but it appears rather tight there.

Nope, the driveshaft has to come out (which means the swingarm has to come off). This sounds like a pain in the ass, but (a) you only have to do it every 10K, (b) it gives you an opportunity to service (inspect and lube) the transmission end splines, (c) inspect the transmission seal, (d) inspect and grease the swingarm bearings, and (e) replace the rubber boots if necessary. Once you've pulled the swingarm (I've done it twice) you find it's really not a bad job.

[sykospain]

Surely yet another depressing example of how this profiteering German manufacturing combine that we're so faithfully wedded to in loyalty is continuously downgrading its component product quality in order to more thickly line its owners' and shareholders' pockets with excessive amounts of loot, so they can all further enhance their already sumptuous and luxurious Rhine-side palaces.

As I've recently discovered when trying to source bulk machined components from China, machine shops there can easily and rapidly shell out extensive runs of acceptable-looking metal items for literally peanuts. But as for the quality...
viz:- my metallurgist friend recently scoped the metal quality of the splined hub fitted to BMW"s Czech-outsourced dry-clutch friction plate in her X-ray spectrometer kit and analysed it as "Chinese pig iron".
And that kind of quality dear friends is what you're paying for in an overpriced BMW motorbike.

[R12RnHouston]

Surely yet another depressing example of how this profiteering German manufacturing combine that we're so faithfully wedded to in loyalty is continuously downgrading its component product quality in order to more thickly line its owners' and shareholders' pockets with excessive amounts of loot, so they can all further enhance their already sumptuous and luxurious Rhine-side palaces.

As I've recently discovered when trying to source bulk machined components from China, machine shops there can easily and rapidly shell out extensive runs of acceptable-looking metal items for literally peanuts. But as for the quality...
viz:- my metallurgist friend recently scoped the metal quality of the splined hub fitted to BMW"s Czech-outsourced dry-clutch friction plate in her X-ray spectrometer kit and analysed it as "Chinese pig iron".
And that kind of quality dear friends is what you're paying for in an overpriced BMW motorbike.

Yikes! Well, I hear you, but I love my R. Chinese pig iron and all.