Replacing bearings ...
 

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[Closed] Replacing bearings in a Shimano XT Dynamo hub

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Has anybody done this? I think mine are done. I'm having to tighten the cups and cones with increasing frequency, it's noisy and the disc rake rotor is now comining into contact with the caliper. All advice welcome!


 
Posted : 29/01/2019 2:47 pm
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I suspect that if you've let it get that bad that the cones / cups will be pitted so will still be rough if you replace the bearings.


 
Posted : 29/01/2019 2:54 pm
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What he said. Although it does sound like you aren't tightening the locknuts onto the cones enough.

I'm sure there is a guide somewhere on taking them apart - if you can replace the cups too (usually just a press fit) then that would avoid a rebuild, but you'd need a new hub. for the cups


 
Posted : 29/01/2019 2:59 pm
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I wondered if I wasn't tightening the locknuts enough, but there is such a fine line right now between there still being play and the axle being stuck and not turning, so it's difficult to put any welly into it


 
Posted : 29/01/2019 3:18 pm
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Currently solved the rotor contacting the caliper problem by loosening the non-driveside cone and tightening the driveside one


 
Posted : 29/01/2019 3:20 pm
 kcr
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There are some detailed breakdown guides online if you search around. You need to be very careful with the disassembly in order to avoid breaking the internal wiring which runs out along the axle. The wiring on my dynohub failed (fatigued or corroded internally) and I found that it was not solderable and there's insufficient room to fit crimp connectors inside.


 
Posted : 29/01/2019 3:22 pm
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I think I've done around 15-20,000 miles on them, is that about right for the lifetime of the bearings? I've always been pretty good about tightening them up


 
Posted : 29/01/2019 3:22 pm
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You need to be very careful with the disassembly in order to avoid breaking the internal wiring which runs out along the axle. The wiring on my dynohub failed (fatigued or corroded internally) and I found that it was not solderable and there’s insufficient room to fit crimp connectors inside.

Yep, what my understanding is that Shimano recommend not changing the bearings on the power output side of the hub. Hrumph!


 
Posted : 29/01/2019 3:24 pm
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I think I’ve done around 15-20,000 miles on them, is that about right for the lifetime of the bearings? I’ve always been pretty good about tightening them up

What about replacing the grease? Have you ever done that?


 
Posted : 29/01/2019 3:34 pm
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What about replacing the grease? Have you ever done that?

Nope! Never! Should I? And how often?


 
Posted : 30/01/2019 11:51 pm
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Yep, what my understanding is that Shimano recommend not changing the bearings on the power output side of the hub. Hrumph!

Indeed, and won't sell you a new cone.

You can chuck new bearings in/regrease with care on the wires. Just make a note of the order you take things off the axle as there's a few things to put back on when you're done.


 
Posted : 31/01/2019 1:37 pm
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15-20000 miles seems to be about the limit of the cones surface IME. I think you're unfortunately looking at a new hub.

Look carefully as I think the Alfine is very similar and considerably cheaper, there may be bargains to be had.


 
Posted : 31/01/2019 1:42 pm
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Amazing, thank you for all of your help!!


 
Posted : 05/02/2019 3:12 pm
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You can buy the LH cone (£10) and you can replace the internal assembly (£70)


 
Posted : 05/02/2019 3:25 pm
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Thanks for that! I'm looking at Rose Bikes and you can buy a decent new one for £70-£90, so I might do that...


 
Posted : 06/02/2019 1:06 pm

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