I recently acquired this used bike and today I set out to service the 8R31 Nexus 8 gear hub following this video.
Due to a, uh, slight counting mistake I filled the tub of ATF to a significantly higher measure than the 95mm Shimano recommends. Stupidly confident in my erroneous counting, I plopped the hub in without checking too hard and went to do something else for a couple minutes.
About a minute later I noticed with a groan that the whole thing was fully immersed, right up to the big outer bearing. By that point there wasn't much to do about it, so I let it complete the 90 seconds immersion like that, and it's been draining into an empty tub for the last hour or so.
My intention to remedy this is to remove as much ATF from the big outer bearing as I can using naphta on a rag, then just grease the heck out of it, hoping between the solvent and the grease it'll give that bearing the denser lubrication it needs.
However, I don't know if there's stuff inside the hub above the 95mm height that wasn't meant to be lubed by the light stuff, and is now going to misbehave.
Should I expect any issues?
by IronMew
2 Comments
The dip line is there to keep the outer shell away from the oil — it’s only there to make putting it back together clean and fast, instead of an oily wrestling session.
Nothing bad will happen to your nexus. There aren’t any braking surfaces there. But do clean it off, so it doesn’t drip down your wheel.
It’s fine. Most of these hubs are literally never serviced and just work, so you’re already ahead of the curve. Nexus hubs probably fail from users shifting under load more than anything else.