Cleaning freehub body

mab bee

I've removed the freehub body from my Ultegra hubs and want to clean it (it has slipped once or twice recently). I also plan to do the same thing pre-emptively on the XTR hub that I use on my touring bike.

So what's the best way to clean the mechanism inside these things? I do not want to dismanle the freehib body completely (I've tried that in the past, and got into a mess). Shimano tell you not to dismantle.

Monty Dog

If it's slipping, then it's probably down to damaged pawls. You can try dunking it in solvent to clean it out and then somehow using a heavy oil or grease, but to be honest, once they're gone, it's not really worthwhile trying to save them

Grunk

Using a thin screwdriver, remove the seal at the back of the freehub to expose the inboard bearings. Take careful note of the orientation of this seal before you remove it.
Place the freehub on some clean cloth with inboard side uppermost and flush with WD40 or similar, turning the freehub as you go. The gunk will go into the cloth.
Turn the freehub over and allow to drain, preferably overnight.
Relube fron inboard side with a good synthetic wet lube like Pedros or Finish Line Cross Country.
Install seal carefully.
Refit and get riding!!

david 142

I'd agree. You cant get spares for the innards so there's no point dismantling, but a clean and relube is worth a try.
You could try to clean out with solvent as suggested above. The other approach is to clean the outside as well as you can and then dunk the unit in something like clean engine oil for a day or two. The idea is that the grease installed during manufacture has thickened because the oil has migrated out, and soaking in new oil will reconstitute the mixture...
And if it doesnt work, you can still try the solvent flush.