Crossthreaded88

I have been looking all over for a tutorial on trouble shooting and or overhauling a Shimano Nexus Internal 3 speed and have had no luck. There are videos on you tube for everything but the Nexus 3. How to take a wheel on and off (Duh!), and adjusting a shifter (easiest thing in the world) are the only ones I could find and those on the old chain pull SA. Is it that difficult that no one has posted a tutorial? Am I expected to treat this misbehaving wheel like a modern television and chuck it and buy a new one? I self taught myself to overhaul a straight coaster brake which was challenging at first but now I can do one practically blindfolded. Can the Nexus be that tough? Mine is slipping out of first gear and free wheeling but second and third are rock solid without issue. When I removed the shifting pin it was slow to come out and was covered in rancid smelling grease. I have not attempted to do anything yet but my first instinct is to clean out some of that disgusting grease by sticking the little red tube on my lube oil can down the shifting pin hole in the axle and let go a few blasts to see if that flushes anything out. I also thought of doing that with Brakekleen but that might not be too good for any plastic parts that may be in there. I hate to write this wheel off as it's connected to a really nice Electra stretch cruiser not to mention the wholesale on a new hub is $60 or retail at $90+. So if there's something out there to guide me in this endeavor, should choose to accept the challenge, I'd be much appreciative for the information. Anything else that anyone might think is helpful will also be appreciated,thanks.

Gresp15C

This might be promising:

https://www.retrocyklo.cz/downloads-d...178-manual.pdf

I've read that cleaning out the grease and replacing with oil is a typical "upgrade" for the newer internal gear hubs.

Crossthreaded88

Agreed this surely helps, thanks. At very least I can disassemble, clean, grease (or not) and assemble to see if that solves the issue with first gear. It would be nice to know if this is a cleaning issue or strictly part replacement.

BicycleSnowplow

Brand new wheel skipping in 1st gear. Had to adjust the shift cable so it was well outside the yellow lines. That fixed the problem for a while. Then it started skipping again in 1st gear climbing hills. So I adjusted the shift cable so the indicator was between the yellow lines and problem went away a second time. Maybe these are just crappy hubs? My last hub locked the brake on twice so I couldn't get it to engage when pedalling after about 7000km. That's why I replaced the wheel. Now dealing with another problem. Nexus 3 hubs seem to develop a lot of problems.

Bought a new bike with nexus 3 on it a few years ago. For no reason, it also developed problems shifting and I had to adjust the cable adjust so the indicator was well outside the yellow lines just recently. It used to work just fine when adjusted according to instructions.

JoeKahno

Three things;

Welcome to the forums, the more the merrier!

Please check the date on the threads before you post. I made the same (minor) goof, resurrecting a thread that had run its course years before I stumbled over it.

More to the point, I'm developing some experience working on Nexus 3 hubs. They are *not* Sturmey Archer, not even close. When properly maintained and not abused they work reasonably well for the casual rider at a price point that won't send them into sticker shock. On the old SA hubs you could get away with fiddling the adjustments until it started doing what you want. Shimano isn't like that. If it isn't working with the correct shifter adjusted to proper specs, it's time to open it up and see what is happening with the internals. I just tore down a SG-3R45 off a Bridgestone Albelt because it seemed to have too much slop in the driver bearings. I had also noticed a couple of minor twitches going into first. It turns out the extra play had allowed it to eat the first gear pawl springs. As it is, a nickels worth of music wire and some bearing balls should get it up and running again. If I'd kept using it until it showed symptoms of a "real problem" I'd be looking at a tray of crunched pieces from the loose pawls getting run through the rest of the internals.

I'll probably never buy a *new* one. If I did, I'd start by giving it the same tear down and cleaning/lube that I give to used hubs. While the Japanese are absolute fanatics about quality control it's my understanding that these hubs are no longer actually built in Japan. Warranties are nice but if I have to eat the cost of the install I want to verify that what I'm installing is within spec. I'd rather void the warranty and know for sure what I have.

Same thing with lubricants. I learned a long time ago working on a wide variety of machinery that having a good quantity of clean lube suitable for the purpose beats trying to stretch the change interval because the recommended lube is too expensive or just not available. I could buy four used hubs for the cost of importing a single can of genuine Shimano hub dipping oil. I use a decent grade of generic water resistant grease on the bearings and lube the rest with full synthetic ATF (automatic transmission fluid). Give it a squirt in the shift pin hole once a month. Tear it down for a clean and repack every two years or 3,000 miles whichever comes first. I live in the tropics so I usually grease hub bearings twice a year at the beginning and end of the rainy season in an effort to keep water out.

What exact model of hub do you have now? What sort of problems is it giving you?

Kovkov

1. Remove rear wheel.
2. Unlace rear wheel.
3. Throw the hub into scrap metal
4. Buy a Sturmey Archer AW hub (preferably one from the 50ies.), trigger shifter and cable.
5. Relace wheel to AW hub.
6. Install wheel
7. Install trigger shifter
8. Install cable
9. Adjust cable tension
10. Enjoy riding without shifting problems for the next 60 years minimum