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-   -   Broken XT hub (https://www.bikeforums.net/showthread.php?t=1166237)

asc99c 02-11-19 05:27 PM

Broken XT hub
 
Hi all,

For a couple of hundred miles, there has been an increasing amount of play in the rear axle on my bike. Part way through my journey to work today, it's started making some noise, and then part way home, started really struggling.

I've given everything a good clean today, so I can see what state it's in, and doesn't look good. The axle can be wobbled quite a bit, although it's all moving freely still. I'd guess the bearings have gone. It's a Deore XT hub which apparently has sealed bearings, so possibly can't be serviced?

Made a 5 second video to show what I mean. Too new to post a link, but it's youtu.be/-j3_d953xnA

Is there much to be done there other than a new hub building into the wheel? Sounds time consuming and expensive?

FYI rear hub has done 5k miles, front hub was replaced 1000 miles ago after a car crash (along with the whole wheel) but I didn't have to pay for that.

Thanks,

Andy

cannonride15 02-11-19 06:40 PM

Shimano typically have cup and cone races, therefore rebuildable ; if you haven't wiped out the cups, that's what looseness will do. Ask me how I know... Cones are readily available, as are ball bearings, cups not so much.
If they are sealed cartridge bearings those should be replaceable. Youtube is your friend on that.

CliffordK 02-11-19 07:42 PM

Your video link:

As @cannonride15 mentioned, the Shimano hubs are rebuildable, and replacement cones and bearings are readily available.

If you ride on it with the axle loose, you risk more damage.

Any bike shop should be able to clean up your wheel, and get it going. Or, there should be instructions online. You'll need a 15mm cone wrench, and a 17mm wrench. I find it is easiest to remove the cassette when working on the hubs, and do the final adjustments from the "non drive side".

You'll probably also need a pile of 1/4" bearings.

aggiegrads 02-11-19 10:08 PM

While you're in there, make sure that the freehub is on tight. You may need to go to a shop to borrow a giant 14mm Allen key.

Dave Mayer 02-11-19 11:21 PM

You should stop riding this- now.

Assuming it is just loose cones/nuts on the axle, it is a 20-minute job to do the following:
  1. Remove the skewer (duh)
  2. Remove the cassette
  3. Loosen and remove the axle from the non-drive side
  4. Pull the 18 (more or less) ball bearings from both sides and clean out the bearing cavities
  5. Check for play in the freehub - you might as well tighten up the freehub while you are at it.
  6. Replace all of the balls with new: for all of a $2 cost for the balls and grease you may as replace all
  7. Check the hub cones for pitting/wear
  8. Properly tighten/lock up the drive side cones
  9. Reinsert the axle and properly adjust the non-drive side cones. Make sure they are locked-up against each other
  10. Reinstall cassette and properly tighten the lockring. As in do not reef on it until the tool explodes.
  11. Done
If you've messed up one of the cones, it is a $10 replacement part. Easy to find online. It takes an extraordinary amount of abuse to irreparably kill a Shimano hub.

If you are dealing with a bike shop on this fix, add 10 minutes of arguing prior to step 1 when they are trying to convince you that you need an entire new wheel. If they are not clear as to how to tackle this, print this list off and show to the shop guys.

Only wrinkle: you actually may have broken an axle on the drive side. This is incredibly rare. If so, add another 10 minutes to replace the axle. At our Co-op, we have 10 pound bin of axles and cones that we sell for basically nothing.

asc99c 02-12-19 01:20 AM

Fantastic, I hadn't realised even the sealed bearings were a replaceable cartridge. Although looking for my hub on the Shimano website I'm sure it's an FH-M8000 which isn't sealed bearings anyway.

I'm short of a few tools to do the job (chain whip and cassette removal tool) and have seen one of the local shops has a 30 price posted online to replace wheel bearings, so quite tempted to go for that.

But hopefully either way that's a lot less expensive than I feared! Thanks all, and thanks for properly posting my link for me!

Koyote 02-12-19 06:53 AM


Originally Posted by asc99c (Post 20790626)
Fantastic, I hadn't realised even the sealed bearings were a replaceable cartridge. Although looking for my hub on the Shimano website I'm sure it's an FH-M8000 which isn't sealed bearings anyway.

I'm short of a few tools to do the job (chain whip and cassette removal tool) and have seen one of the local shops has a 30 price posted online to replace wheel bearings, so quite tempted to go for that.

But hopefully either way that's a lot less expensive than I feared! Thanks all, and thanks for properly posting my link for me!

If you need to get back on the road quickly, take it to that shop. Though that price is a little high.

trailangel 02-12-19 09:25 AM

You should have stopped riding it as soon as you noticed play......several hundred miles ago. Hub probably toast now.

davidad 02-12-19 11:44 AM


Originally Posted by asc99c (Post 20790626)
Fantastic, I hadn't realised even the sealed bearings were a replaceable cartridge. Although looking for my hub on the Shimano website I'm sure it's an FH-M8000 which isn't sealed bearings anyway.

I'm short of a few tools to do the job (chain whip and cassette removal tool) and have seen one of the local shops has a 30 price posted online to replace wheel bearings, so quite tempted to go for that.

But hopefully either way that's a lot less expensive than I feared! Thanks all, and thanks for properly posting my link for me!

The hub is not a radial bearing model. All of shimano hubs are cup and cone bearings. The seals in all bike hubs are basically dust seals.

Dave Mayer 02-15-19 03:03 AM


Originally Posted by asc99c (Post 20790626)
Fantastic, I hadn't realised even the sealed bearings were a replaceable cartridge. Although looking for my hub on the Shimano website I'm sure it's an FH-M8000 which isn't sealed bearings anyway.

We need to clarify some terminology. Better Shimano hubs (such as XT) are well sealed against dirt and water intrusion. Better sealed than any other hubs I have, and I have many wheelsets featuring some very expensive hubs.

if you operate your bike in water, or use a pressure washer to clean it, water will get into the hub, causing early failure.

Shimano hubs use ball and cone construction, as opposed to standard cartridge bearings. It is possible to make either a well or a poorly sealed hub with either bearing type.

Actually, some of the worst hubs I've owned have used cartridge bearings.

fietsbob 02-15-19 11:38 AM

Only throw away; NDS loose ball cups pitted , or spoke holes torn out, other than that , you can find replacement parts..



MTB wheels often discarded when rim is damaged , so parts , used , can be found in bike shops..

The one here has a big basement broken wheel pile.





...

asc99c 02-18-19 12:22 AM

You're quite right Dave on the terminology. Before my first post on here, I thought I was dealing with a cartridge bearing on the hub. As in couldn't be opened up and repaired. When in reality it's not.

The bike shop opened up the hub, and the problem looks to be that the axle is bent, very slightly. I'm not using it as a serious MTB so the only really heavy impact would have been the car crashing into me 1500 miles / 6 months ago.

The bearings did actually look very clean, and still had a good coating of grease so the seals have been excellent, both against dirt and the slightly excessive cleaning with Morgan Blue when I started looking at the hub!

asc99c 02-18-19 10:43 AM

Hmmm, well ignore everything on my last post!

On the opposite side, everything inside had rusted away, looks like the seal was completely gone. Half the bearings had worn to dust. Apparently it's an unusual design with an oversized axle and small bearings. Internet suggests this model is disappointing in terms of reliability.

My local bike shop that fixed the front wheel after a crash didn't sound keen on fitting a replacement XT hub now I recall. I've got Hope Pro 4 in the front wheel.

AnkleWork 02-18-19 11:25 AM


Originally Posted by Dave Mayer (Post 20795595)
Shimano hubs use ball and cone construction, as opposed to standard cartridge bearings. It is possible to make either a well or a poorly sealed hub with either bearing type.

+1
Not sure why that is so quickly and frequently forgotten, but it does not make human nature look good.

bakerjw 02-18-19 02:09 PM

As mentioned. Bearings and cones are cheap to replace. Shimano insists that the cup and cone bearing model is the best and suffice to say, they can be falling apart and still function for the most part.
I've personally never seen a cup get too badly worn, but cones? They pit really bad sometimes.
The worst thing about the rear hubs is that the freehubs get sloppy and they are almost as much as a new hub for replacement parts and finding the part can be hit or miss.
A good set of hub tools is really helpful too.


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