Bicycle Mechanics - My broken Nexus 8 hub
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03-31-11, 12:21 PM
About a month ago, the Nexus 8 hub on my winter bike broke. I put it aside since it was the end of winter and I finally quit playing with my new toys and decided to take the Nexus hub apart.
To make a long story short there is a lot of side to side play although the axle is not broken. I do see something like a retaining clip loose on the inside of the drive side seal. I suspect that is the problem, or a symptom of a larger one. The whole mechanism rotates quite freely and easily around the axle and there doesn't seem to be any contamination from water. The grease itself seems to be pretty clean, which is great after 4 years. Anybody got any experience with this?
03-31-11, 02:22 PM
I have no advice to offer about maintenance or repair as my Shimano IGH has not needed any maintenance yet. I just wanted to say I am amazed at how clean the inside of that hub is after 4 years of winter riding! And that gives me a good feeling when I think about my Alfine hub and my understanding that the Alfine is very similar tot he Nexus except for improved seals!
03-31-11, 02:33 PM
I'm amazed There's very little dirt contamination.The seals must work well.
04-01-11, 07:22 AM
Well I took the drive side apart today and found the ball retainer and ring gear retainer clip had both broken.
The question is why? I'm afraid that I will have to disassemble the rest now to be sure some other secret defect doesn't come back to haunt me.
04-01-11, 12:00 PM
Perhaps (and like I said before, I have no experience rebuilding these hubs) that that was as far as the salty and dirty water from winter riding was able to enter the hub and corrosion killed those components.
04-01-11, 12:10 PM
Shimano might warranty the parts or maybe the hub, might want it for inspection. Some of the internals are the same as WRX turbo's according to Shimano. I would consider that fairly strong.
04-08-11, 06:11 AM
Have you had a chance to take it apart yet? Last week I serviced a Nexus inter7 for the first time. It's a little different from the inter8 but I was able to use Sheldon's instructions with no problems. I took my time and gave my self a lot of space to lay all the internal gears/pins/rings down onto. I did run into a fitting problem and probably pull it apart and put it together about 20 times. Needless to say, I can probably piece one pretty quickly now. Looking quickly at your OP, the second and third picture show that there seems to be a gap in the assembly. The bottom part of the gears showing should fit into the corresponding ring below it. I'm not sure if you already started removing lock rings when you took that picture. Anyhow, keep us updated on your progress.
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