Shimano Nexus sg-3d55 Inter - 3 hub troubleshooting

[LI-ghtcycle]

Hello all, been running one of these Nexus Inter-3 IGH for about 8 months, and I'm having an issue with 3rd gear slipping. I think I might have run it a bit with out it being properly adjusted at first, hoping I didn't damage something, but I am running a BBS02 (Luna stock settings) so nothing crazy, and it has never slipped out of gear in 1st or 2nd, but 3rd has been problematic since day one. I started playing with the adjustment of the cable, and got it a little more reliable, but under load of even pedal power alone, it slips out of 3rd pretty regular.

After the first time I started playing with the shift cable tension, I thought I had solved it since I was able to climb a moderate hill at full power with no issues, but it is back to slipping again.

Have yet to find any good videos or other info on rebuilding this hub, and I see that others are putting quite a bit of power through one of these hubs with no issue, so I am wondering if someone can steer me to a good video or other resource? Thanks!

[eCue]

A guess is a part was installed incorrectly or was made for a different bike.

Make sure the yellow and red dots on the hub washers line up correctly and also when the cable is connected make sure its yellow dots line up as the instructions instruct.

Might be the wrong size pushrod on the hub

There are two lengths of Nexus 3 pushrods (that go into the hub) available a shorter one, which is for 168mm length axles, and FW/roller brake hubs (175mm axles) is difficult to find through distributors.
The difference is 8mm, but it’s enough that the hub won’t function correctly. Chances are wherever you bought parts for it assumed that there is only one size, but their parts catalog usually say “Nexus 3 pushrod”, and doesn’t indicate the length.

The shorter one is 81.85mm long (Shimano part #Y 33R 98080) and the longer is 86.85mm long (Shimano part #Y 33S 98180). You can also improvise

Get and older, solid (no spring) Nexus pushrod and cut it down to the correct size. This makes ZERO difference in hub operation, is cheaper than the “correct” one, and doesn’t take two weeks to show up from wherever you ordered it from.

[amberwolf]

Looks like the full article/thread is here
https://bicyclesinnewcastle.com/2012/03 ... -problems/

[LI-ghtcycle]

Great thanks all! I am ordering a new hub so I can swap out the internals assuming the hub shell isn't damaged (hopefully not since both 1st & 2nd work fine) and then I can see what is going on with 3rd, or if there is a difference in the length of the push-rods, both of these hubs were ordered at my LBS, so shouldn't be an issue, since I am ordering a complete assembly directly from Shimano. It sucks if I end up having to swap the internals to fix it effectively, but it is a relatively cheap fix, and I would want to replace the oil inside too anyway in an over-haul. I fear I might have damaged it from the beginning, ridding it with out first adjusting it, and only when it had been slipping for a bit did I start paying attention to how it should have been adjusted oops!

[LI-ghtcycle]

I also found some great info from Sheldon Brown's website: https://www.sheldonbrown.com/shimano333.html

The grease is pretty reasonable for this hub, but wow, the oil form is pretty expensive! Gonna have to save up for the $70 "maintenance oil" that it should be dipped in every 5000 km (3107 mi)

I also found a troubleshooting guide here:

https://web.archive.org/web/20130926221 ... 0Guide.pdf

[eCue]

Transmission fluid is a good alternative to the Shimano oil