Shimano Cassette Body cleaning/regrease

[TunaAndBikes]

I've had issues with my shimano freehub after a few k kms of dirt, rain and the occasional snow (eg slipping under load, loud pinging when pedaling).
Thought it was the spokes, got the wheel re-tentioned but no dice
I'm pretty positive it's the cassette body that's slipping rather than the cassette or chain, which are virtually new.
To be added; chainrings are also in decent condition, so doubt that's where it's coming from.

Anyone ever attempt to clean/relube your shimano cassette body?
How'd you do it? did it work well and long?
Thinking Brake cleaner inside the cassette body followed by 10W40 (which is the oil I use for my fancy hubs, as per manufacturer's reccomendation) and possibly some greaes

It's a 6800 hub, but don't want to spring 50$ prior to trying something out.

[clyde the point]

Replacement bodies are available. Sounds easier.

[unterhausen]

I had an Ultegra cassette body break in half. Not sure if they can be rebuilt. Bike shop had a takeoff cassette body

[slambers3]

You can sometimes have some luck slipping lube through the seals of the free hub depending on the model, however in my experience its only a temporary-at-best repair. Shimano did not design these to be serviceable. If the free hub is failing, your best move is to replace the unit and move on.

[dddd]

The Ultegra freehub body is sealed at both ends.

Short of pulling out the locking cone from the freehub body, there is another way to get oil inside of the ratchet and bearings.
After removing the axle (and perhaps also the balls if they won't stay in place), one can position the hub horizontally and introduce a quantity of about 15 drops of oil directly behind the sealing ring. After allowing this oil to settle briefly, slowly tip the hub (slightly at first) toward the left side, which allows the oil to flow more readily around the bearing cup through the annular space between the cup and the outer shell of the freehub body.

This usually only works if the hub bearings have never been heavily over-greased to the extent that grease now clogs the annular space around the driveside axle bearing cup.

Usually the axle bearing balls will start to fall out of place before the above task is completed, but usually this can be corrected without having to fully R&R the axle bearings. It might be best on an older hub to remove the axle bearings first, and if the shield is removed then there will be direct access straight into the annular space around the cup. At that point, a blast of lubricating oil through a stretch-tapered applicator straw (photo) would be able to blast oil past any excess grease that is sealing the annular space.


Lastly, for a full inspection and clean-out of the freehub body, a 13/16" socket can be carved up to allow removal of the reverse-threaded locking cone that is integral with the driveside axle bearing cup:

[xnetter]

I have a couple Shimano hubs in my household that could use this procedure and I've been putting it off for a while. Just the odd slip/clink once in a while; probably just a case of dried out lubricant.

There are some YT videos that at least give a visual on what is going on inside these freehubs, eg. https://www.youtube.com/watch?v=X9gIEG1db0s&t=599s

It's true that modern hubs are way easier to overhaul. The Hope that I have comes apart super easy and then it's just popping out the 4 springs and pawls, clean-reassemble-relube, and that's it.

KJ

[GregL]

While Shimano freehub bodies are relatively inexpensive, I'd try to clean and re-lube yours before pitching it. Remove the freehub body from the hub shell, remove the rubber seal from the back of the freehub body, and then immerse in a degreasing fluid for a suitable amount of time. All the old grease should dissolve and run out. Once the freehub body interior is cleaned out, gently use compressed air to remove any remaining cleaner. Then re-lube the freehub body from the backside using an oil that is compatible with whatever grease you use on the ball bearings on the outside of the freehub. Re-install the rear seal, re-install the freehub body on the hub shell, re-install the axle assembly (including ball bearings, cones, and locknuts). Parktool has a good online tutorial.

I've used this method for years. I had one Ultegra 6402 freehub for over 20 years. When I sold the wheel in which it was installed, it still rolled like new.

Greg

[austex]

I have the old Morningstar Freehub Buddy, no longer made.
http://www.bikepro.com/products/hubs/hubacces.html


JA Stein has this:
https://www.steintool.com/portfolio-...eehub-flusher/

[xnetter]

Originally Posted by austex

JA Stein has this:
https://www.steintool.com/portfolio-...eehub-flusher/

That Stein tool looks interesting. Might have to try that one.

KJ

[TunaAndBikes]

Don't have an air compressor to dry out the innards
I'll try something that's super volatile and re-lube/grease see where that takes me