Trying to Replace Shimano freehub body

reallybrokendave
reallybrokendave Posts: 12
edited March 2011 in MTB workshop & tech
I've got a spec 2007 rockhopper disc. I've been having more and more problems with the freehub so decided to replace the freehub body. On the specialized website it's list as a M475 free hub.

I read in an old thread at a M510 / M525 freehub body should be compatible so bought one as it was supposed to be slightly better.

When swapping it over though I've found that the dustcap doesn't neatly sit on top of the bearings, it leaves about a 2mm gap which surely can't be right.

Now i'm just stumped, does this mean that the M510 isn't compatible? It can't require larger bearings as the body size is the same.

any suggestions?

thanks,
Dave.

Comments

  • nicklouse
    nicklouse Posts: 50,675
    the cones used in the two hubs are different but it should not make much difference.

    pics of how it is.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • reallybrokendave
    reallybrokendave Posts: 12
    Yeah this is what i don't understand. I'll take some pics tonight and post them
  • mister p
    mister p Posts: 405
    There is a slightly different body fitted to an M475 hub, it is the same as an RM40 hub. The part number for it is 3SL 9803.

    Because the cones used on an M475 are different to the cones on an M510 hub if you try to fit an M510 body you will get a gap.
  • Koiler
    Koiler Posts: 513
    im sure you can swap everything from inside the donor hub over, if you swap the races, bearings, axle, cones and freehub, then there shouldn't be any issues as im sure the actual hub body is the same
  • mister p
    mister p Posts: 405
    From reading the OP he has only bought a freehub body, not a complete rear hub.
  • Koiler
    Koiler Posts: 513
    mister p wrote:
    From reading the OP

    ...it would seem this is not something i did very well... :lol:
  • mister p
    mister p Posts: 405
    You are right though, to get the new body to fit properly you would need to swap the cone on the driveside.
  • reallybrokendave
    reallybrokendave Posts: 12
    thanks for all your feedback.

    I haven't had a chance to sort the pictures out but having another look at it the problem is that the dustcap on the new body does not sit in deep enough into the body and so leaves about 2mm clearance from the bearings.

    I tried the old & new dustcaps and the problem is the same. On the inside of the body there is a thread (on both old and new bodys) but on the new body there is a lip at the bottom of the thread (closest to the bearings) that the dustcap sits on. problem is that it's too far away from the bearings. On the old body there was just more thread so that the dustcap could sit down onto the bearings.

    I'm stuggling to understand why its like this ...
  • mister p
    mister p Posts: 405
    It is like this because the cone in the M475 hub is 2mm longer than the cone you are using. The lip holds the dust cap in the correct place for the longer cone but will leave a gap when you try to fit it to your hub.
  • reallybrokendave
    reallybrokendave Posts: 12
    ah, the penny drops. So it's the cone that's keeping the bearings in place (i'm clearly new at this).

    Does this mean the the cone for the M475 is still holding the bearings in place and i don't need to worry about the gap? Is there any knockon effect of having the gap there?

    Or should I just get a driveside cone for the new body?

    Or should i just go and get a freehub body for the RM40 as, as you say, they are the same piece of kit?
  • Koiler
    Koiler Posts: 513
    in order to get rid of the gap you either need the correct freehub for the hub you have now, or a complete new hub that you can swap all the internals from into your current hub. This will give give you brand new bearings, races, cones and axle and of course, a new freehub that will fit
  • reallybrokendave
    reallybrokendave Posts: 12
    thanks,

    getting a new hub and replacing the components sounds like a fine idea - i think i'll do that.

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