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Front u-joint failure: how common?


BendBill

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[i'm NOT going to vent. I'm NOT going . . . ]

 

But I do have a question for the mechanically savvy.

 

Just when my 03 RT is finally broken in and running strong and smooth at 33K, the driveshaft failed SUDDENLY the other day. At least I was close to home.

 

BMW of Western Oregon just called and said the front u-joint failed. They will take off the swingarm to assess any other damage. For now, however, it's a new driveshaft at least.

Service dept says BMW will not cover part of repair because the warranty expired over a year ago .

 

I LOVE this ride, I really do. But my question is: How rare is this type of failure? I never noted any seeping or fluids and I really do ride it conservatively [if that is even a factor]

 

 

Thanks for any info

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russell_bynum
[i'm NOT going to vent. I'm NOT going . . . ]

 

But I do have a question for the mechanically savvy.

 

Just when my 03 RT is finally broken in and running strong and smooth at 33K, the driveshaft failed SUDDENLY the other day. At least I was close to home.

 

BMW of Western Oregon just called and said the front u-joint failed. They will take off the swingarm to assess any other damage. For now, however, it's a new driveshaft at least.

Service dept says BMW will not cover part of repair because the warranty expired over a year ago .

 

I LOVE this ride, I really do. But my question is: How rare is this type of failure? I never noted any seeping or fluids and I really do ride it conservatively [if that is even a factor]

 

 

Thanks for any info

 

That's pretty rare. I'd wonder about it happening with such low miles on the bike. That seems strange.

 

I do know Eebie had a U-joint fail on his bike, but it had a bazillion miles on it at the time. His was pretty ugly...punched a hole in the swingarm and did a bunch of other nasty damage requiring the use of a Sawzall to get the bike apart. eek.gif

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[i'm NOT going to vent. I'm NOT going . . . ]

 

But I do have a question for the mechanically savvy.

 

Just when my 03 RT is finally broken in and running strong and smooth at 33K, the driveshaft failed SUDDENLY the other day. At least I was close to home.

 

BMW of Western Oregon just called and said the front u-joint failed. They will take off the swingarm to assess any other damage. For now, however, it's a new driveshaft at least.

Service dept says BMW will not cover part of repair because the warranty expired over a year ago .

 

I LOVE this ride, I really do. But my question is: How rare is this type of failure? I never noted any seeping or fluids and I really do ride it conservatively [if that is even a factor]

 

 

Thanks for any info

 

 

Bill, there can’t be very many of those failures..

 

Any idea of what broke on the U-Joint.. Was it the trunion, or a cap, or is the metal surrounding the cap split, or possibly a cap slid out of place.. .. Or is it too mangled to tell?

 

If the bike hasn’t been abused I would pester the heck out of BMM for at least parts compensation.. Maybe a 50/50 split offer anyhow..

 

Hope there isn’t anything else torn up in there..

 

Twisty

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If the bike hasn’t been abused I would pester the heck out of BMM for at least parts compensation.. Maybe a 50/50 split offer anyhow..
Yeah, that is really low miles for a failure like that. I would think that there had to be some kind of materials/manufacturing defect involved.
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Bill,

As you've heard that is pretty rare at your mileage. I had the front u-joint fail (lack of lube) on my K11LT at about 85K miles. One cross piece was totally blue but it got me home.

 

Mick

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When BMW of Western Oregon service dept calls back next week, I'll get extra details--and hope that there is no more damage. It's a pain to do this long distance.

 

Does anyone know how I begin contacting BMW? I intend to pursue the matter, especially since I already had a thrown rod at 15K, which was covered under warranty. They installed new matching pistons--hence my longer-than-usual-wear-in period: the engine had just begun running smoother and stronger.

 

I assume I start the complaint ladder with the dealer. I'll call him tomorrow. BMW of Western Oregon did a great job on my previous warranty work, and their last service had the motor in fine form.

 

Again, thanks for the replies of Russell and the info from 3 tech moderators.

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DavidEBSmith

Mine blew up at 107K miles. There was no warning. It went out at 65 mph on the Interstate.

 

It knocked a hole in the swingarm and bent the output shaft on the transmission, which is something you should have checked. Total bill for for replacing the swingarm, driveshaft, opening the tranny and replacing the output shaft, and throwing a new clutch as long as it was apart was about $3500.

 

Here's what it looked like:

 

ds1.jpg

 

ds2.jpg

 

 

This is the swingarm:

 

ds5.jpg

 

ds7.jpg

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Very interesting David. At least two points had been cracked long enough to rust prior to failure.
Did that rust occur before or after the failure? If before then that is interesting... I had always assumed that such an incident would be the result of a catastrophic bearing failure. If it was the yoke itself that actually let go then that might be a worthwhile area to inspect whenever one has the bike apart.
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DavidEBSmith

Maybe - the pictures were taken some months after the failure, and I don't know under what conditions the broken parts were stored at the shop.

 

I noticed recently that when the RT sat outside for about 2 weeks while the broken fuel injection manifold was still leaking significant amounts of gas frown.gif , the top of the sidestand bail, where the paint is rubbed off, got a nice spot of bright orange rust on it. I've never seen that happen when the bike is parked inside the garage for the same length of time.

 

So the broken driveshaft parts could very well have been sitting outside at the shop and started rusting then. But, I would have to say that the rust almost certainly indicates areas that were stressed and fractured enough to be prone to rusting, whether it was before or after the total failure.

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David, there is so much damage there it is very difficult to tell what happened..

 

The one shaft loop is torn open (a possible cause of the failure) & the other loop is completely missing (is it still attached to the U-Joint?) If it is still on the U-Joint that end could have ripped the shaft loop off in use (especially if there was a metal defect or previous crack)..

 

Was that a used bike or has someone other than you ridden it away from your sight?

 

I used to rip drive shafts apart like that on my race trucks & could tear the end cap loops off the tube or split the cap loops open like you show there (that didn’t happen from normal usage though)..

 

Twisty

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Ah, then I'm going to guess that the rust formed after the failure. I'd be surprised if a part that was fractured badly enough to rust like that could have lived long enough to rust like that, if you follow my meaning, unless the bike sat unused for a very long time. I kind of doubt that was the case here... wink.gif

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DavidEBSmith

The one shaft loop is torn open (a possible cause of the failure) & the other loop is completely missing (is it still attached to the U-Joint?) If it is still on the U-Joint that end could have ripped the shaft loop off in use (especially if there was a metal defect or previous crack)..

 

What you see is what was left, other than a crumbly mess of needle bearings and metal fragments that fell out when they finally got the swingarm off the bike. (As Russell mentioned, they needed to use a Sawz-all to cut off the swingarm pivot, as you can see in one of the photos).

 

It's hard to tell what order things happened in. All I know is that somehow the front u-joint became disjointed, and because the rear joint was still attached to the rotating rear wheel, the rotating shaft flailed around inside the swingarm and beat itself to death.

 

I'm pretty much the only rider of the bike - most people refuse to touch it, let alone sit on it, let alone ride it. It's hard for me to imagine what you could do riding a stock RT to abuse a u-joint to death. I still hold to my theory that I did something to it when I was replacing the shock (shortly before this happened) and lost my grip on the swingarm with the rear wheel and shock off, so it dropped to an extreme angle.

 

On the other hand, when I posted about this to Internet BMW Riders, a bunch of people reported u-joint failures in the 95k to 120k miles range, which this fits perfectly.

 

But the OP's failure at 33K is way too early to attribute to normal wear and tear. Even if there is a propensity for failure, it's at much higher mileage and is rare even at that.

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Looks pretty nasty, whats the interval on inspection of these. Should I run out and get some of the red stuff and the white powder spray dye penetrant to check for cracks at my 30 k ?

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russell_bynum

whats the interval on inspection of these

 

When you're riding down the road, and suddenly hear a loud bang followed by a loss of power and a resonating "THWAP THWAP THWAP THWAP THWAP THWAP THWAP THWAP THWAP THWAP THWAP THWAP THWAP THWAP" as you slow to a stop, and you find a large hole in your swingarm....that would probably be a good time to inspect the driveshaft and U-joints.

 

 

grin.gif

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Grisly pics, Eebie. Thanks, I think.

 

My swing arm was intact, though it's yet to be removed for inspection inside. I'll keep my fingers crossed for an intact output thingy from the trans.

 

I'd be surprised if there was any further damage because I was only doing 20-30 when I first heard a clacking sound, at which point I pulled over within 150 yards.

 

I'll also try for pics to determine most likely cause of u-joint failure.

 

I'll pass along more when I learn anything.

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