Service Freehubs?
 

My son and I were lucky enough to be given a pair of about '93 vintage Trek MTBs complete with rigid forks and many problems. I've gone through them and repacked the wheel, bottom bracket, and headset bearings. Relaced one of the wheels with a new rim, replaced a canti brake that was missing parts with a mini-v, spent a fair amount of time getting the shifters to work right again, and just did a lot of general clean up and replacement of the missing little bits. I figured I was done but started thinking about the freehub (Shimano 7 speed). I figure they have very little load when coasting and none when pedaling so they really shouldn't need attention unless they act up. Is this right or should I pull them apart and shoot a little oil at them? I've never serviced a freehub (I know - if I can relace a rim on a wheel a freehub should be cake), so is this the time when I ought to learn?

Thanks for any input,
Labrat

They generally run fine forever.

But if you're looking for an excuse to pull em apart, they often have some play which can be eliminated by removing a shim or two, which theoretically should result in slightly better shifting.

Pull the cassette and spindle, then you should be able to see a couple of slots in the edge of the bearing cup. Use an appropriately sized bit of plate to crack it while the body's on the hub (it has a left-hand thread), then use a 10mm allen key to remove the cassette body from the hub. You should be able to continue unscrewing the cup by hand - do it over a rag. Grease is a requirement for reassembly.

Thanks Kimmo,

These are 20 year old entry level MTB's that should work fine for my sixth grader to knock around on or, in my case, a backup or guest bike. Since they "generally run fine forever", I will probably just leave well enough alone.

Labrat

Yep, that's what I'd do. As long as they're freewheeling fine and not causing problems I'd leave them.