Originally Posted by
sweeks
I think the only good alternative to the "dip" is grease, which pretty much requires disassembly. The gears are in sub-assemblies that aren't too difficult to get off the cluster or put back. The sub-units only need disassembly for a really thorough cleaning and (IMO) can be left intact for re-greasing.
The oil dip is much easier. I have found that gear oil (I use Royal Purple 75W-140, which has similar properties to the Shimano Alfine oil and is 20-25% of the cost) has less of a tendency to run off than ATF. After the dip, I let the cluster drip for a half hour before reinstallation in the hub. Even though my Nexus hubs have relatively poor seals, I have not had a significant leakage problem.
I pack the bearings with the regular Nexus grease, which theoretically helps with keeping the oil inside the hub.
Speaking of Nexus grease, when I started looking inside Nexus hubs, the "official" grease was a black paste which looks like it contains molybdenum disulfide. My first Nexus 8-speed hub used the same grease, seemingly. My second N-8, a "red band", had a white grease, like lithium grease. I use the black stuff on all these hubs, partly because I bought two tubes of it and partly because the black stuff is easier to clean off the parts.
If you haven't seen Aaron's Bicycle Repair, they have some good pictures:
Internal Gear Hub Service.
Steve
The white grease is slightly runnier than the moly grease, which Shimano now specifies for their coaster brake hubs. It also mixes readily with the nexus oil, which I suspect is the bigger plus to it; after servicing one, riding around the block, and opening it up to satisfy my curiosity, the internals were a pretty uniform blue-ish white, with no distinguishable grease or oil, just the amalgam of the two.
BTW, if you are going to strip the hub down to the axle, it is easiest to clean the parts with diesel fuel, as you don't need to strip it off when you are done cleaning...which is prohibitively difficult, if you don't have all the tools to re-assemble the internal assembly.