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U joints


OlGeezer

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A friend of mine had u joint failure on his RT. It totally locked up and torqued his drive shaft.

 

Is it difficult to check u joints? Checking the final drive is pretty easy to do, I'm hoping checking the u joints will be as easy.

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Morning OlGeezer

 

Depends on what you are working on-- if on an 1100/1150 BMW then rear U joint is fairly easy to get to & check out but the front is a real pain.

 

For the rear just drop the final drive back.

 

For the front U joint the entire swing arm has to be removed.

 

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Peter Parts

I have a belief that half the bikes out there with that stupid Paralever contraption have misadjusted rear Paralever bearings.

 

So, if you have some adjusting in your future (esp. to replace with the bronze jobbies,.. a real good idea), you are half way to the inspection.

 

Not common for the u-joints to fail. Some enthusiastically driven bikes have torn rubber bushes in the middle of the shaft, but that should be detectable as soon as it happens, I'd guess.

 

BTW, some number of bikes also have their u-joints out of synch. A BMW scandal.

 

Ben

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DR -

 

Should I then just have them replaced as a precautionary measure or just wait for them to fail, if in fact they will?

 

Thank you,

 

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Afternoon OlGeezer

 

On your BMW the U joints are not serviceable separately, to replace the U joints you need to replace entire drive shaft. (big money)

 

The rear U joint is the usual failing one but not in all cases.

 

You might check the rear for RUST & notchyiness. Rust around the U joint caps & yoke is a usual sign that you have U joint problems in your future.

 

I have felt & seen a number of drive shaft & U joint issues on any number of vehicles through out my life time. If a person knows what a failing U joint feels like they can usually detect a U joint failure well in advance to it letting go completely. Problem is, not every rider has that background so could ride into total failure condition unaware.

 

As to "WILL THEY FAIL"-- no way of really knowing as there have been a number or reported failures but the majority of BMW's don't fail a U joint or drive shaft.

 

If your bike has been power washed a number if times around the final drive area that could lead to an earlier rear U joint failure due to water intrusion. Same with riding through rivers or high moisture inside the swing arm.

 

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HI Ben, I am not trying to be inflammatory or provocative, but is there ANY feature you do like about the Oilhead BMW?

Andy

 

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HI Ben, I am not trying to be inflammatory or provocative, but is there ANY feature you do like about the Oilhead BMW?

Andy

It's not just the Oilheads.

So far I have not seen a reply yet of him to anything regarding BMW bikes, that could even be remotely seen as "not" negative.

I have to be honest, you lot are a lot more tolerant then I am.

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OlGeezer, I had the rear u-joint on my '96 RT fail last summer somewhere around 168,000. I had no indication that the failure was coming. The failure occurred while traveling down a highway at an unhurried pace...no strong acceleration or decelleration. Because of the bike's high miles I'd been careful to check for abnormal slack or noise in the driveline. I'd stopped for breakfast and fuel shortly before the failure and would have thought that if failure was just around the corner it would have manifested itself in some manner, but such was not the case. Inspection of the removed shaft led me to believe that once the u-joint started to fail the destruction progressed exponentially.

 

The front joint showed no signs of wear. I installed a used shaft which I purchased on ebay.

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I did some research and, according to the microfische on the A & S Website, the u joints are integral to the drive shaft. It seems like replacing one without the other is not possible. They are one part number. The drive shaft with the u joints is a little over $700 retail. I realize there is quite a bit of labor involved, but I have NO IDEA how my friend's bill came to $4k.

 

Does anyone have a WAG on what the shop labor would be to replace the drive shaft with the u joints? I'm guessing it shouldn't be more than 8-10 hours or $650-$800 around here. That would put the total bill somewhere around $1,500. Am I missing something? Although that number doesn't sound bad for a 10 year old bike with 163k miles on it, I doubt if I would have spent $150 per year on chains and sprockets. Right? Of course, I haven't bought many chains and sprokets lately.

 

FYI, my crown gear was replaced at 108k miles or 55k miles ago. Since I checked it regularly, the failure occurred in the service bay of my local BMW dealer. That's exactly the place I would like my drive shaft to fail if in fact it does fail.

 

 

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Morning OlGeezer

 

As you noted that drive shaft is only available (new) as an assembly. At least from parts houses & dealers.

 

 

The BMW drive shaft has staked in U joint caps. It is possible to replace them (IF) you can find a proper sized U joint & have the equipment to press the old ones out & the new ones in (could be as simple as a large hammer, a suitable sized socket, & bench vise).

 

Seeing as the U joints are used for a long run of motorcycles there probably are some in the OEM size available out there somewhere (I doubt BMW speced out a special U joint size as it is much/much cheaper to design to a an already existing sized U joint).

 

Because of their smaller size my guess would be the replacements (if you can find any) would not come with retainment clips & the caps would not be machined for any type of retaining clip. That means the replacement U joint would have to re-staked in place & perfectly centered in the yoke. That can be done in a home shop with the correct equipment & knowledge or by a specially shop that does custom drive shafts & gear set ups (there are usually a few shops like that in every big city).

 

Cost wise it is probably cheaper to have U joints put in your existing shaft but by time you figure shipping both directions, the cost of the U joints & labor, "& the downtime involved" in most cases it is easier & much quicker to just install a new or used shaft).

 

As for your friends $4K bill, no way to know without seeing his repair receipt. It could easily have involved seal replacement on the final drive & transmission, the new drive shaft, possibly new swing arm pivot bearings, maybe a crown bearing, & who knows what was damaged if the shaft failed while being ridden at speed (I have seen the swing arm beaten so badly by the un restrained flailing shaft that they are unusable). About the only thing I can say is he didn't have a simple shaft replacement. Sounds like way more was also repaired or replaced along with the shaft.

 

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About the only thing I can say is he didn't have a simple shaft replacement. Sounds like way more was also repaired or replaced along with the shaft.

 

I agree.

 

Would you have any idea what the shop labor charge would be to replace the driveshaft including the u joints?

 

I'm probably naive in thinking that, once the final drive is removed, the drive shaft can be extracted without dropping the swing arm, right?

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---

 

 

 

I'm probably naive in thinking that, once the final drive is removed, the drive shaft can be extracted without dropping the swing arm, right?

 

Afternoon OlGeezer

 

Nope, you would think it should but it won't. Due to the depression in the swing arm for tire clearance the front drive shaft yoke just won't pull back through the swing arm. SO, the entire swing arm needs to be removed to get the shaft out.

 

As far as dealer cost to install a drive shaft I have no idea not cheap though.

 

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Maybe I am just lucky, or too stupid to know better, but I just replaced the drive shaft on my '98 RS (165,000 miles) with a used shaft (28,000 miles) due to a 'notchy' sound and feeling when turning the rear wheel by hand on the centerstand.

And I did it WITHOUT dropping the swingarm.

Pulled the f/d off. Pulled the drive shaft out (took a pretty good tug, but it slipped right out). Pushed the replacement shaft back up the swingarm using a long thin piece of aluminum to guide it to the back of the transmission. Shoved hard and the front splines went together.

Maybe everything is just easier when you don't know you can't do something.

And I still use the OEM BMW bearings at the pivot pins.

 

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Maybe I am just lucky, or too stupid to know better, but I just replaced the drive shaft on my '98 RS (165,000 miles) with a used shaft (28,000 miles) due to a 'notchy' sound and feeling when turning the rear wheel by hand on the centerstand.

And I did it WITHOUT dropping the swingarm.

Pulled the f/d off. Pulled the drive shaft out (took a pretty good tug, but it slipped right out). Pushed the replacement shaft back up the swingarm using a long thin piece of aluminum to guide it to the back of the transmission. Shoved hard and the front splines went together.

Maybe everything is just easier when you don't know you can't do something.

And I still use the OEM BMW bearings at the pivot pins.

 

Wow! I AM impressed!

 

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52k??? Pshaw. The RS had 160,000+ when I replaced it.

I put the bike up on the centerstand and turned the rear wheel by hand. I could feel the 'notchiness' and hear it slightly. When I pulled the fd off, I grabbed the ujoint and swung it back and forth, and could feel the hitch in its giddyupandgo.

I am sure someone will quote a failure at 52,213 miles or somewhat, but believe failure is very rare on bikes with less than 100k.

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With 52K on my '02 1150RT, should I be concerned? What kind of test or check can I perform?

 

I don't think you need to worry. The driveshaft joints from my old RT are still nice and tight, and it has 126k miles on it.

 

The only way to check is to remove the driveshaft from the bike and check the U-Joints for play. I wouldn't worry about it until you get to the 100K+ range. Even then, I wouldn't stress about it.

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I wouldn't worry about it until you get to the 100K+ range. Even then, I wouldn't stress about it.

 

Gulp!

 

Not to stress? I worry about getting stranded in BFE, a place I tend to frequent.

 

I guess I better get it checked.

 

 

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Bruno replaced both joints on my RT 7 years ago for $300. He said one of the joints was dry with no grease. That was at 114k miles.

Cheap insurance, IMO.

 

George

 

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