Joe Bikerider

It’s been about 5 years that I’ve been riding this bike, Shimano says lubricate the hub every two years. I did that after two years so I figured it was time to do it again. I remember the first time being pretty straightforward this time was more of an adventure. I’ve collected some links here to help me next time and maybe someone else too.

First thing is to remove the wheel and begin hub disassembly, see link below. Mount the hub in a bench vise with drive side down, tighten on the flats on the axle. On the non-drive side (up) remove lock nut and cone to expose bearings 3/16 balls x 13 in a retainer. Part 12 on list below. Don’t lose any of them (see below).

Lift off the hub shell and proceed per instructions. Don’t let the snap ring fly across garage floor and get lost.

I cleaned and lubed the innards and proceeded with reassembly. That’s when I discovered the missing ball. I got a replacement ball from the local ACE hardware. Since we all know that loose balls are better than having a retainer I laid the retainer aside and put in 13 balls embedded in the new grease. Bad idea.

When reassembled the wheel made some weird squealing noises. Like the brake pads were rubbing. They weren’t. Or the fender, it wasn’t. And weirdest of all, the next morning when I started out there was no noise at all until after about a mile and it was squealing again.

I got home and turned over the bike and in frustration gave the wheel a spin. It was squealing with nothing rubbing. I slept on that. The next morning I took off the wheel and opened up the hub. I could see now that a couple loose balls had snuck through the gap in the snap ring and were on the wrong side.

I dug out the loose balls, retrieved the retainer and carefully put the balls back in place. Put it all back together and the wheel runs silently again. Wahoo!

The bottom link below is the only place I found that sells the 13 ball set. Any other suggestions would be appreciated. Thanks.

SG-8R31 parts

https://si.shimano.com/pdfs/ev/EV-SG-8R31-2783B.pdf

Dissasembly of 8 speed hub

https://www.sheldonbrown.com/nexus8/pages/12.htm

Source for 3/16 x 13 balls in retainer

https://www.bikesomewhere.com/shiman...x13-y34r98070/

dsbrantjr

At 2 bucks apiece I would put a few ball/retainer sets aside for the future, although the balls should last a loooong time if kept lubricated regularly.

fietsbob

some people replace grease with an ATF dunk, done regularly..







..

Joe Bikerider

I find it best to follow the manufacturers suggestion. The model of this hub specs special grease which I used. Other models spec the dunk procedure using some expensive Shimano branded oil, I have one of those hubs too. As part of all this I found out that a LBS (Big Dave’s) has that oil and knows the dunk procedure. In a couple years I will probably be visiting them. Hope the fires will be out by then 😀

fietsbob

Ex Napa, With many acres of places I've ridden my bike, burning,

But now on OR coast, with a light rain. currently..

Joe Bikerider

Sounds nice. 83F and smokey here. What I didn’t mention in my long story was that those days it was over 100F every afternoon. Hard to concentrate on little ball bearings while sweat was dripping off my nose. 😓

sweeks

One of my Nexus 8-speed hubs has almost 10,000 miles on it. Once a year, for 10+ years, I've opened the hub and dipped the gear cluster in synthetic gear oil similar to the oil Shimano recommends for the Alfine 11-speed. I use the recommended Nexus grease on the bearings. The hub works well, and there's no wear on the races beyond a polished ring.
FWIW, I've used the same synthetic gear oil (Royal Purple "Max Gear" 75W-140) for over 8,000 miles in another bike with an Alfine-11 hub.