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I had developed a weird vibration on my bike. It would only do it while giving it some gas and would do it in every gear. If just cruising on flat ground without giving any more gas, the vibration would go away. It's only been doing this for about 30 miles or so, but it has gotten progressively worse quickly. I decided it wasn't in the engine,(I hoped... after all the crank bearing problems I've had in the past) but somewhere in the drive, so I planned on changing out the middle drive and U-joint. The middle drive oil smelled a bit burnt, but not bad. If this didn't fix it, I was going to swap out the final drive.
I removed the U-joint bolts, took the rear wheel off, and dropped out the entire swingarm. After checking the U-joint, it was obvious that it was the problem. It pivoted one way easily, but the other way it felt like the needle bearings were rectangle.
I took apart the U-joint and found the first yoke still greased nicely and in good shape. The 2nd yoke... not so good. This is the entire contents of one of the neddle bearing cups.
The material had gotten hot enough that it melted some of it into a pool of metal at the bottom.
On the other side of this end, the cap was very rusty and void of any grease, but all the needle bearings were still there. Although they were there, the lack of grease allowed them to deeply notch the shaft of the U-joint.
These two pics are from the worst side...
In this last picture, you can see the end of the U-joint shaft. Some U-joints are hollow and you can grease all four sides with one grease zert. These aren't hollow though. What you could do if interested when you had it down that far is to take it apart periodically and grease it, though I recommend being careful. Two of the retainer clips shot off into nothingness in my garage when they came off. Another option... is to leave the U-joint in tact, drill the center of each cap and install a grease zert. This would keep the balance right also under high rpm. When you applied grease to the zert, it would fill that hollow point in the U-joint shaft, then squirt out of the slots you see on each side at the top into the bearing cups.
OR... you could simply leave it alone.. lol. I am the only one I ever heard of having a problem with this. I have been riding with a new U-joint boot in place (Yes drain hole at the bottom) for @ 2 years, so it's not like it was getting washed out in the rain all the time. It just seems weird to me that the thing only seemed to have a problen in the last few miles when it's obvious that this has been a problem for a long time.
So, just for your info. Not trying to be a scare tactic, but it just makes me wonder about all the people that come on here and talk of weird vibrations..
Tod
I removed the U-joint bolts, took the rear wheel off, and dropped out the entire swingarm. After checking the U-joint, it was obvious that it was the problem. It pivoted one way easily, but the other way it felt like the needle bearings were rectangle.
I took apart the U-joint and found the first yoke still greased nicely and in good shape. The 2nd yoke... not so good. This is the entire contents of one of the neddle bearing cups.
The material had gotten hot enough that it melted some of it into a pool of metal at the bottom.
On the other side of this end, the cap was very rusty and void of any grease, but all the needle bearings were still there. Although they were there, the lack of grease allowed them to deeply notch the shaft of the U-joint.
These two pics are from the worst side...
In this last picture, you can see the end of the U-joint shaft. Some U-joints are hollow and you can grease all four sides with one grease zert. These aren't hollow though. What you could do if interested when you had it down that far is to take it apart periodically and grease it, though I recommend being careful. Two of the retainer clips shot off into nothingness in my garage when they came off. Another option... is to leave the U-joint in tact, drill the center of each cap and install a grease zert. This would keep the balance right also under high rpm. When you applied grease to the zert, it would fill that hollow point in the U-joint shaft, then squirt out of the slots you see on each side at the top into the bearing cups.
OR... you could simply leave it alone.. lol. I am the only one I ever heard of having a problem with this. I have been riding with a new U-joint boot in place (Yes drain hole at the bottom) for @ 2 years, so it's not like it was getting washed out in the rain all the time. It just seems weird to me that the thing only seemed to have a problen in the last few miles when it's obvious that this has been a problem for a long time.
So, just for your info. Not trying to be a scare tactic, but it just makes me wonder about all the people that come on here and talk of weird vibrations..
Tod
(Sold back to Maximan)
- NOW IT'S FOR SALE! $1,800 OBO
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