Gatorfreak

I have a Dura Ace 7700 hub with some play in the freehub body and I believe it is the source of a slight rattle as the cassette vibrates but otherwise performs ok. The rattle is annoying though. I'm wondering what my options are?

1. Buy another Dura Ace 7700 hub off ebay and replace the freehub body. Is this even possible? I'm hoping this could be done without having the wheel rebuilt?

2. Buy a new hub and have the wheel rebuilt with it. I'm not too concerned about the rear hub matching the front.

From the googling I did, it doesn't sound like the freehub body can be fixed or tightened but maybe it can be replaced from another hub. I'm very open to ideas that I'm not aware of.

Thanks

HillRider

If the freehub body itself is loose, remove the axle and see if the 10-mm hollow bolt that fastens it in place has gotten loose. If so torque it back to spec. . If the cassette is loose on the freehub body, retorque the lockring and, if it'a a 10-speed cassette, did you forget the 1 mm spacer that should be behind it? A replacement freehub body is easy to install but be sure your isn't just loose.

I also have a 7700-series freehub with 55,000 miles on it and it works perfectly so they are pretty durable hubs.

Gatorfreak

I have the 1mm spacer. With the cassette off, I can feel some play in the freehub body. I've never tinkered with hubs but I like to learn how to do my own maintenance. Do I need two 15mm cone wrenches to get at where I can try tigthening the 10mm hollow bolt?

Edit: Found this excellent video: https://www.youtube.com/watch?v=a9mAHypsjdo
I'll order a pair of cone wrenches and check that 10mm bolt.

Andrew R Stewart 

There does need to be a small amount of slop in a freewheel or freehub body if running loose balls (as the DA does). How much is allowable is the trick. This is one of those aspects of bikes that is hard to translate to words and then to the reader's fingers.

Is the slop enough so that the cogs move far enough to cause auto shifting or chain scuff on adjacent cogs while riding? If not then I don't know if there is actually a problem worth doing something with. Andy.

pressed001

Me too. Great hubs.

This is a good point. A very slight amount of play is considered ok. It isn't affecting his shifting so I don't think it is too significant.

Gatorfreak, if you want to learn about hubs and how to service them, the 7700's will be a wonderful starting point. They are easy peasy to service. Don't forget to pick up a good 10mm Allen when you get those cone wrenches. If you have lots of miles on the hubs already, you may also want to pick up some Shimano Dura Ace grease and re-lube the bearings.

Gatorfreak

Thank you all for the tips. I ordered the tools and grease. I'll post back with results.

HillRider

I hope you didn't order 15 mm cone wrenches since the 7700 rear hub requires two 14 mm cone wrenches. The cone itself has 14 mm flats and the locknut is made so it also requires a 14 mm cone wrench. The usual ability to use a standard open end or box wrench on the locknuts doesn't work for these hubs.

davidad

If you do need to replace it the free hub body from an Ultegra or a 105 will fit.

davidad

The cone wrenches for that hub are 14mm.

Gatorfreak

Thanks for the 14mm correction! I was able to get the order changed before it shipped out.

Both Ultegra 6800 and 6700 will work? That's probably what I'll do if I need to replace.

HillRider

6700 is 8/9/10-speed and should be a direct substitute except you may need different cones and seals. 6800 is 8/9/10/11-speed so it's a bit wider. If you substitute it, you will want to slightly redish the wheel too.

Crankycrank

Yes they can be refurbished, re-lubed, and adjusted to some extent. If you believe in preserving salvageable parts, are poor or cheap (I'm all three) it's worth the effort to try and fix it if it's actually too loose or worn. A good video here to disassemble your freehub body. https://www.youtube.com/watch?v=X9gIEG1db0s Shimano freehub bodies sometimes come with thin shims, which you'll see when disassembled, to accomplish the proper bearing preload/ spacing and may be found at your LBS but can be very hard/impossible to find. Most likely a good flushing and lube and possibly loose ball bearing replacement will do the trick but a very loose body is usually a sign that it's time to replace if it affects your shifting. It does take a fair amount of work to overhaul a body, most don't bother and just buy a replacement but it is possible.

rmfnla

Also remember to adjust the wheel bearings to allow a small bit of "play" in the axle when the wheel is not installed.

It gets taken up when the QRs are tightened down when the wheel is mounted in the frame...

Dave Mayer

Congratulations in that you have about the best road hub ever made. The 7700 has high quality hardware that includes very hard and smooth bearing cups, top quality cones, great sealing, and the titanium freehub that saves a fair amount of weight relative to the Ultegra and below versions.

Plus it is compatible with a broad range of replacement which includes the balls, cones, axles and freehubs. Finally, it features Shimano's superior rear hub design, that places the bearings at the end of the hubs, where they should be, and it has the superior loose-ball construction.

This hub will provide a lifetime of service, if properly maintained. Almost every part of this hub, including the bearing cups (yes, the cups) can be replaced.

I have thrown out a lot of hubs and wheels in my past, but this little gem is worth saving, even if it means spending a couple of hours to take apart the freehub down to the million little ball bearings and pawls.

Yes, the freehub can be replaced with the cheaper steel version (105, Ultegra etc.), but the titanium freehub is a nice feature. Replacement Ti models are very expensive, unless you can salvage them off of dead 9 speed Dura-Ace or XTR hubs.

Finally, be careful about freehub replacements. I doubt the 6800 or 7900 or 9000 series freehubs will be compatible. Check the specs carefully - I think these units use an oversized axle with smaller balls than the 1/4" 7700 bearings.

Earl Grey

Are they actually available? I have a set of these and have never seen even the cones available anywhere but NOS on eBay (considered buying another set of hubs to have spares).

pressed001

This is great advice and will prevent you from ruining your bearings/cones by overtightening. I usually adjust mine so there is just a tiny bit of play. It takes some re-tries (tightening, feeling, then loosening again..etc...)to get it right.

Dave Mayer

Breaking down your question into 2 parts: yes they are available. Are they available as a spare part sold by Shimano or one of its outlets? Absolutely not.

Shimano will absolutely discourage you here, as will every shop on the planet. Maybe 1 in 100 shop mechanics have ever tried this, although the work involved is about the same as replacing a cartridge bearing in a hub shell. So about 30 minutes work, which includes tearing down the donor hub.

Going from memory, the O.D. of the non-drive side bearing cup is exactly 28.0mm. The cups accept nine 1/4" ball bearings. For a replacement cup, I have used a cup from a thrashed XTR hub. Interestingly, a cup from an old Campy Record freewheel hub should also work.

Earl Grey

Ah, gotcha - we aren't necessarily talking about using the part numbers specified by Shimano. Buying NOS hubs seems about the only way to obtain those! Still, that is very interesting to know, thanks.

davidad

The cups on shimano hubs are not replaceable. I have a 7700 and replaced the freehub body with the one from an Ultgra. I add a heavier piano wire spring on the pawls so that I can regrease the body using a Morning Star free hub buddy.

I can't get the left side dust shield from shimano. They don't make it any more.

Dave Mayer

I've done it. Read my previous posts. This requires the same tools and technique as removing and reinstalling cartridge bearings. Not all Shimano hubs provide enough space for the jaws of the extractor tool to catch on the lips of the bearing cup. A minute of inspection will tell you if you have the space.

Gatorfreak

I overhauled the hub. Much easier than I thought. The bearings were basically dry in there. Maybe the rattle was from the dry bearings? I used the shimano hub grease and put it back together. Need to do a test ride now. The freehub body still has a little play so we'll see.

If that didn't solve the problem, will a 6700 freehub body work with this? Those are $20-30.

davidad

Yes. I think any 8p or 9sp freehub body will work.

rmfnla

I've seen replacement Ti freehub bodies on eBay for $50 or so...

Gatorfreak

The noise is gone! Went around the neighborhood for a test ride and it was silent! I guess the bearings just needed some grease. Makes me worry the bearings inside the freehub body are in a similar state but for now it seems to be ok. The body still has a little play in it but everything is functioning and quiet.

Thank you all for the tips. I'll make this an annual thing. I bought the wheels used and I guess previous owners never serviced the hub.

pressed001

Very cool. Consider replacing the bearings themselves because they are most likely worn out. Where they bling-bling shiny or were they a gunmetal gray? The cones might also be worn out. If they have a ridge or ring worn into them they should also be replaced. But you could nevertheless still enjoy riding without further servicing, so long as it runs.