Berre

I saved a Koga bike from scrap. It has seen little or no maintenance in it's miserable life. Rust all over it; sad.
So I would like to take it apart and restore it to it's original glory.

Since I have worked on vintage bikes only, I have no experience with the modern stuff, like the Shimano Hyperglide freehub. I already read Sheldon's info about removing the cassette. I still lack some info about any maintenance of the HG freehub's bearings.

In fact I wonder if the HG freehub needs any maintenance in the first place, since it seems to spin fine. Though I guess it may need some fresh grease now and again. Can the HG Freehub be disassembled in order to reach the bearings, or is this hub a "no-servicable-parts-inside" kind of thing? Do I need any special tools?

Thanks a lot in advance for any tips on this issue.

operator

10mm hex to access the freehub. You can drip lube into it, don't know about overhauling.

HillRider

The freehub body can be removed from the hub shell after the axle and bearings are removed. It is held onto the shell by a 10 mm hollow hex bolt with conventional right-hand threads.

Most freehub bodies have a rubber seal ring on their rear face that can be removed to allow easy lubing of the bearings. Drip a lot of Tri-Flow or similar light oil into the annular space, spin the body to distribute the oil and let the excess drain. Grease is not needed and can cause problems in cold weather. If there is no seal ring, just drip a lot of oil into the parting line between the stationary core and the rotating shell.

Replace the seal ring, bolt the freehub body back onto the shell, grease the races, and install the bearings and axle. Adjust the bearings properly and you are good. Disassembly of the freehub body, like disassembly of a freewheel, is not needed or a worthwhile exercise.

bcoppola

HillRider has it pretty well covered, but I'll add a bit: drip the oil in & spin as he describes but keep repeating until clean oil comes out. That way you know it's clean.

Outboard motor gear oil is often recommended; I've been using it with no problems. It's cheap too.

I just rescued a seriously grungy & gritty Hyperglide freehub by soaking it in mineral spirits (paint thinner) overnight. let it drain, and then did the oil drip procedure. Smooth as silk and quiet!

Berre

Thanks a lot for those answers! I'll give it a try.

Berre

I removed the hub from the freewheel. It was fairly clean. Just dripped some teflon lube in it and gave it a few spins. Runs very smoothly now.

Thanks again, all of you, for your help.