Servicing my Shimano Deore hub

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Reassembling the hub

hub-06

Drive side cone in very good condition.

I've read that the cones show signs of wear before the hubs, especially the cone on the drive side. At this point I realised I hadn't needed to service my hub at all.

hub-07

Oiling the freehub.

I wasn't removing the freehub but I thought it a good idea to drip some light oil inside it. I then made sure the cup was clean and laid the new ball bearings on a layer of lithium grease. I'm not sure if this is the best type of grease to use but it was recommended as suitable by a local bike shop. I packed more grease on top.

hub-08

New ball bearings in Weldtite white lithium grease – drive side.

I reassembled the drive side of the axle and fitted it back through the hub from the drive side. The dust cap, seal rings, and washers are compressed between the cone and lock nut tightened together before it's pushed through. You have to be careful to leave enough exposed axle thread to sit in the chain stay drop out.

hub-09

Cone screwed back on non drive side, bearing packed with grease.

I turned the wheel over and screwed the other cone down the axle until it was hand tight. This is the tricky bit. If it's tightened too much the wheel won't spin on the axle because the hub assembly will be squeezed between the drive side and non drive side cones. There needs to be a slight amount of play in the axle, but not too much or the axle will stay loose. If everything is right this play will disappear when the wheel is back on the bike and the skewer is fully tightened.

But I couldn't seem to get this right. The axle stayed loose no matter how much I tightened the cone, and even the skewer, so I took everything apart again and a ball bearing fell out – the ball I'd lost when dismantling the hub, so I had ten balls where there should be nine! How did that happen?

hub-10

Tightening the non drive side cone a little, not a lot.

Finally, back on with the left side lock nut assembly, tightening the lock nut and spacers hard against the cone. It's worth having Shimano's technical documents handy to check the various rings etc are all in the right order. And last of all, the cassette goes back on.

Now I have a bicycle wheel 100% built by me.

Summary:

  • Remove non drive side dust cap, lock nut, and spacers
  • Remove cassette
  • Remove non drive side cone
  • Pull axle out from drive side
  • Remove ball bearings on both sides
  • Clean cups and cones, then inspect and replace if required
  • If dirty, clean axle, seals, spacers, nuts, etc
  • Apply grease and new ball bearings to cups on both sides
  • Reassemble drive side axle leaving enough thread for drop out
  • Make sure drive side lock nut is screwed on tight
  • Push axle through hub from drive side
  • Screw non drive side cone on hand tight
  • Check axle play – it needs a very slight amount
  • Put non drive side lock nut assembly back on and tighten up
  • Check wheel on bike with skewer tightened
  • There should now be no sideways play of wheel but it should spin
  • Adjust non drive side cone tightness if required
  • Put cassette and dust cap back on

« Page 1: dismantling the hub for regreasing

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13 comments on “Servicing my Shimano Deore hub”

  1. Hilary wrote:

    Years ago I used to enjoy stripping down my hubs but that was under the strict supervision of my mechanically minded ex. Somehow I've not had the nerve to do it on my own, I always have a great fear of making a perfectly running bike unrideable! I leave the pleasure to Brian, the excellent mechanic at Roberts, when my bike goes for her annual service.
    Maybe one day I'll pluck up the courage to follow your very informative instructions and try it on my other bike.

  2. Patrick wrote:

    I know what you mean about messing up a working bike. This job on the hub is actually very easy but I didn't know that before I did it. The thing is to remember where each of the rings, washers, seals etc goes, and which way round. It's very messy too. I had filthy grease everywhere and had to keep washing my hands to take the photos. A workshop would help. I just put a piece of hardboard on the carpet.

    The most difficult job I've come across on a bike is adjusting the front mech, even with a repair stand. I've never managed to set the one on my tourer so the chain doesn't rub one or the other side of the cage.

  3. Kern wrote:

    Great step-by-step instructions, great photos, and an impressively clean workspace. I have never had the nerve to get down to the bearings, but based on your post I just might give it a whirl this season.

  4. Patrick wrote:

    Thanks Kern. Worth a go, I think. It's helpful to have the technical diagram. For my rear hub: this one from Shimano (384Kb PDF).

  5. Hilary wrote:

    'But I couldn't seem to get this right. The axle stayed loose no matter how much I tightened the cone, and even the skewer, '

    This would have freaked me out completely, I can feel myself breaking out into a sweat at the very thought! :)

  6. Patrick wrote:

    LOL

    I'm still not sure about the white grease. The original one was green.

  7. Chris wrote:

    Patrick wrote: At this point I realised I hadn't needed to service my hub at all

    I suppose that's the nature of preventive maintenance, servicing the hub before it there are any signs of wear. Something I'm not particularly good at, I'm afraid.

    Patrick wrote: ...so I had ten balls where there should be nine! How did that happen? ... Tightening the non drive side cone a little, not a lot.

    There's your answer: it's magic!

    I would add at the beginning of your summary that it's worth holding the wheel firmly between your hands at the locknuts before trying to dismantle the hub. Try spinning the wheel (you may need a third hand for this if you can't manage it with your thumbs) to get a feel for the resistance you should have when you reassemble everything. (This, of course, assumes there is not too much play already as a result of worn bearings.)

    I learnt this the hard way after I had overtightened the locknuts on the front hub of an old bike years ago. After a few miles two circular cracks appeared on the hub where it flared out to accommodate the bearings 😳

  8. Patrick wrote:

    Yes, a magic ball, definitely. When I took the old balls out I gathered them up and put them on the sideboard. Two rolled off and fell on the carpet, but I could only find one. Then I cleaned the cups and put in the new balls – nine in each side (from 18 in the packet). The missing (old) ball must then have jumped back in!

    So when I'd tightened the cone and put the wheel back on the bike I could see the rim was out of true – because of the ten balls, not nine. This same ball fell back out when I took the cone off again.

    On this Shimano hub system overtightening the cone locks the wheel and prevents it from spinning, because you are essentially squashing the hub between both sets of balls.

    (not drawn by me, and the first to take a photo of a freehub preload spacer gets a free inner tube – provenance and UK delivery address required)

  9. Mary wrote:

    Great report Patrick. I always wondered what the chain whip was used for!

  10. Garry wrote:

    I've often done it. I hate it. Getting the tightness right so that when the skewer's tightened there's no play, but it's not "gritty" to rotate is truly finicky. If it's loose it'll wear. If it's too tight you'll get galling and pitting. Galling is right.
    Nowadays I don't touch the hub unless I have evidence something is wrong. I feel it's bad luck!! (I don't actually believe in luck or otherwise)

  11. Kern wrote:

    My daughter and son-in-law just finished a visit. I mentioned to Andrew that my derailleur needed some adjustment. Before I knew it he had the bike on the stand and had stripped down my rear hub to the bearings. It turns out he raced during his teenage years. Every weekend he and his mates would re-grease their hubs with only the most minute amount of grease. For his pains I set him up on the CompuTrainer and introduced him to Titanium Man!

    Andrew servicing rear hub
    Andrew servicing the rear hub

  12. Patrick wrote:

    I bet he made it look easy too – re-greasing the hubs I mean. Did you make notes?

  13. Nigel bainbridge wrote:

    I took my rear wheel to the shop as my cassette had about 1/8 in end float. seemed excessive. took the cassette off and the free wheel hub could be pulled in and out about a 1/8 in. i left it with them and come back to me saying hub bearing had seized causing the end float. the free wheel was working as it should and I just finished a ride never heard any bearing noise I only found end float when I was washing down bike. i was convinced the freehub securing bolt had started unscrewing. i have not got specific tools but or would have investigated it myself. is the seized bearing a plausible cause.

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