Noisy bearings in Shimano freehub unit
#1
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Noisy bearings in Shimano freehub unit
What could be the reason for freehub bearings getting noisy after cassette has been tightened down on a freehub body? They almost sound like a grinding stone. Without cassette and some tacky Lucas engine Assembly (might be similar to Phil wood Tenacious oil) lube they feel smooth and quiet. As far as I know only low grade freewheels such as SunRace had noisy bearings in them. Surprisingly bearings in Shimano freewheels were the quietest so far.
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Does the freehub body have and bearing slop? Especially loose ball freehubs (and freewheels) really like a tiny amount of slop. If there is slop and excessive noise then the bearing surfaces are likely worn/rough. Mounting a cassette does change the tonal aspects of what noises might be happening. Noises can sound louder or deeper with greater mass solidly attached to the noise maker. Long distance i would not want to make claims of this or that as these things can be subtle sometimes and what one calls a wrong noise another might not ever hear.
BTW running a dry bearing is rarely a good thing for noise or wear. Andy
BTW running a dry bearing is rarely a good thing for noise or wear. Andy
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Which one? The one at the drive side or oil seal at the back of the freehub unit? The dust cap at the drive side came out too easily by fingers for some reason. Couldn't get it back in straight despite no bends in it. The seal at the back of freehub unit appears to be reusable since it's made out of soft rubber.
Last edited by sysrq; 10-19-21 at 09:19 PM.
#5
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Does the freehub body have and bearing slop? Especially loose ball freehubs (and freewheels) really like a tiny amount of slop. If there is slop and excessive noise then the bearing surfaces are likely worn/rough. Mounting a cassette does change the tonal aspects of what noises might be happening. Noises can sound louder or deeper with greater mass solidly attached to the noise maker. Long distance i would not want to make claims of this or that as these things can be subtle sometimes and what one calls a wrong noise another might not ever hear.
BTW running a dry bearing is rarely a good thing for noise or wear. Andy
BTW running a dry bearing is rarely a good thing for noise or wear. Andy
Last edited by sysrq; 10-20-21 at 04:51 AM.
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IIRC from the other thread, these are new hubs OP disassembled.
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Any chance you're just freakishly sensitive to any noise at all? You seem to start a thread about anything that spins and isn't silent.
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Which one? The one at the drive side or oil seal at the back of the freehub unit? The dust cap at the drive side came out too easily by fingers for some reason. Couldn't get it back in straight despite no bends in it. The seal at the back of freehub unit appears to be reusable since it's made out of soft rubber.
I bring it up because I once thought you were supposed to remove the dustcap when servicing the bearings. It got bent up, and it rubbed on the cone when everything was reassembled, so I was curious if that could be the source of your noise. Especially if the cassette lockring causes the distorted dustcap to rub against something only when it's tightened. If you can double check that it's not warped, and that there is a layer of grease between it and the cone, that should keep it from causing any real problems when everything is reassembled.
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Yeah, I meant the outer one. In the future, don't try to remove it. You can remove the bearings, wipe away the old grease, apply new grease, and re-install the bearings with it in place. Just get creative with your pinky.
I bring it up because I once thought you were supposed to remove the dustcap when servicing the bearings. It got bent up, and it rubbed on the cone when everything was reassembled, so I was curious if that could be the source of your noise. Especially if the cassette lockring causes the distorted dustcap to rub against something only when it's tightened. If you can double check that it's not warped, and that there is a layer of grease between it and the cone, that should keep it from causing any real problems when everything is reassembled.
I bring it up because I once thought you were supposed to remove the dustcap when servicing the bearings. It got bent up, and it rubbed on the cone when everything was reassembled, so I was curious if that could be the source of your noise. Especially if the cassette lockring causes the distorted dustcap to rub against something only when it's tightened. If you can double check that it's not warped, and that there is a layer of grease between it and the cone, that should keep it from causing any real problems when everything is reassembled.
The dust cap was covered with thin layer of grease.
Last edited by sysrq; 10-20-21 at 05:20 AM.
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Sealed bearing that you removed the seals and re-lubed? Might just be some dust or grit. Probably won't hurt much long term. And if it does, then you can fork out another 3 or 4 dollars for a new bearing set and resist the urge to peek.
After awhile the bearings will have the grit or sand pulverized and it'll be somewhat quiet again. You could try cleaning and lubing again.
After awhile the bearings will have the grit or sand pulverized and it'll be somewhat quiet again. You could try cleaning and lubing again.
#12
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Sealed bearing that you removed the seals and re-lubed? Might just be some dust or grit. Probably won't hurt much long term. And if it does, then you can fork out another 3 or 4 dollars for a new bearing set and resist the urge to peek.
After awhile the bearings will have the grit or sand pulverized and it'll be somewhat quiet again. You could try cleaning and lubing again.
After awhile the bearings will have the grit or sand pulverized and it'll be somewhat quiet again. You could try cleaning and lubing again.