Dura Ace 9 speed free-hub maintenance
This is a pretty old hub, mid-90's but I don't know the model #. The wheel spins freely and is smooth, but the free-hub seems to be a little loose and sounds a little grindy when free-wheeling. Is the free-hub user-serviceable? Any maintenance advice or pointers to sites with service information?
Andrew R Stewart
The freehub is able to be removed from the hub shell, Also able to be dissambled. But most will just flush, drain through, with solvent or light oil. Then lube with a medium weight oil. This can be done still attached to the shell but is slow to do. The wear won't be adjusted in any case. Andy.
+1. I have a set of these 7700-series Dura Ace hubs with over 50,000 miles on them and they are still in perfect working order with the original cones, races and freehub body.
Originally Posted by Andrew R Stewart
The rear hub comes apart just like any other Shimano freehub except you will need two 14 mm cone wrenches since the locknut has very thin 14 mm recessed wrench flats, and is not the usual 17 mm hex nut. Once the axle is out the freehub body removes with a 10 mm hex key in the hollow bolt. When the body is off, there is a rubber seal ring on its back side that can be carefully removed and the internal bearings flushed and relubed. Use a lot of oil (I like Tri-Flo) and let the excess drain. Replace the seal and reassemble the hub.
If push comes to shove replace it with an Ultegra free hub body.
AFAIK (if the DA cassette body is the same as other Shimano units), you can actually dial out the play.
Before you remove the cassette body, and remove the dust cover (often hard to remove without damaging, but you can fill the space between the balls and the lockring with grease if you're concerned about weather protection, it's pretty shielded anyway). You'll see the cup the axle bearings run in has a couple of notches in its outer edge. Get a bit of thick steel plate and cut/grind it to fit the notches, and crack the cup (it's a left-hand thread).
Then remove the freehub body. Now you can unscrew the cup (over a rag) and you'll find it's a double cup with 25 tiny balls under it. There's another 25 in the back.
Under the cup is a stack of shims; after cleaning and greasing the internals, try leaving the thinnest one out.
Reassembly involves a bit of a trick; you have to sit the back race of balls in a fillet of grease on the cone. Give the shell a bit of a twist to get over the pawls as you put it on and then make sure the shims are in place before setting the outer race.
Finish tightening it when it's back on the hub; bingo.