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  1. #51
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    Slipping / cracking shimano xt freehubs

    I have been having a LOT of problems with multiple failures of new Shimano XT freehubs in the last few years. Making a loud cracking noises, or worse, slipping, usually on engagement after freewheeling, but sometimes later, even after a few crank revolutions, which is even more unexpected and dangerous.

    All of them have been Shimano XT and bought form Chain Reaction Cycles in Ireland.
    I have had the same problem with 2 complete rear wheels (the most recent only purchased a couple of months ago), and 2 XT hubs (bought specifically for the freehubs because it was better value than the freehubs alone).

    Having had yet another failure today (one so bad I can't just ignore or live with), and reading up on the net, I still can't tell for sure whether CRC in particular has had a very large bad batch, or if Shimano has put out bad stock to multiple shops, distributors, and suppliers.
    One thing is for sure, this is not an isolated problem. There are multiple instances documented online.

    Today’s freehub will go in the bin. I have swapped it out for one I had on a spare wheel. This new one has also only had a couple of months use, but I remember also suffers from occasional cracking noises and slips. So, I have removed the seal from the rear, and flushed it out with oil before fitting.

    While I hope this works (should grease be making the pawls stick from the factory), I suspect they are just plain defective, and that Shimano should have issued a safety warning and recall.

    If anyone knows of a safe and reliable freehub body that will fit to XT hubs, please post, as I need one for both my bikes!
    Last edited by xr600; 08-26-2012 at 01:57 PM.

  2. #52
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    Wow I thought the XT hubs were good, I was just about to buy a set of these to fit my new ZTR Flow 26" - 32 Hole White Rims.

    Shimano XT M756A Rear Hub Black, 135mm QR, 32 Hole
    Shimano Deore XT M756 Disc Front Hub Black, 32H, 100mm


    GULP!
    Last edited by Trail_Blazer; 08-26-2012 at 08:28 PM.

  3. #53
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    I wouldn't try to put you off buying those wheels, I would go ahead anyway.
    What I am talking about here is a potentialy HUGE batch of faulty Shimano freehubs, which I think I have been falling foul of, for what seems like at least the last few years.
    I'm not going to blame CRC here either, unless they have been having a lot of complaints from others, and still selling them of course.

  4. #54
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    Hi schristie11,

    I have been doing some more on-line research and would like to retract my last post advising to go ahead and buy that rear hub anyway.

    The XT756 is (I think) the hub I have on my 2 mountain bikes now.
    (I have also taken the freehubs from 2 new XT hubs that had the small flange)

    NONE OF MY RECENT FREEHUBS HAVE NOT SLIPPED OCCASIONALLY FROM NEW!

    All the Shimano freewheels (on the cross country biased ranges) appear to be the same junk.

    They all regularly have the same problems(I have experienced 1 & 2)
    1) Slipping freehubs due to bad pawl engagement
    2) Straight from new, the cones work loose
    3) Grating noise leading to freehub seizure
    4)The cones actually self tighten causing complete hub faiure

    Time will tell if the slipping can be cured by flushing out any grease with oil

    You may find posts on forums from people saying htis only affected some older hubs. Not true, they are still on sale.

    My advice is, don't but any XT (or any Shimano for that matter) rear hub from recent years (who knows if 2012 /2013 hubs will be OK).

    The front hub seams to be great ... as it should be!

  5. #55
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    Quote Originally Posted by schristie11 View Post
    Shimano XT M756A Rear Hub Black, 135mm QR, 32 Hole

    GULP!
    Avoid this one. The 756A is more like a glorified Alivio rear hub. Mush worse sealing than plain 756 and I suspect worse quality bearing races too. Entirely different innards than good old 756, of which there are a HELL of a lot in use currently, even to the point it's the go-to hub for value minded cyclists (around here at least, I get to build more wheels around those than any other hub).
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  6. #56
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    Ug!
    This is getting a lot more complex than I wanted . lol
    Now I'm wondering if I should pony up for a Hope or king or DT rear hub.

  7. #57
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    Quote Originally Posted by schristie11 View Post
    Ug!
    This is getting a lot more complex than I wanted . lol
    Now I'm wondering if I should pony up for a Hope or king or DT rear hub.
    Those hubs are great, can't really go wrong with either one.

    My hub of choice is Hope Pro 2 SS/Trials, but it's really loud. There are some technically superior hubs, but value wise, this one is better in the end. May not be your cup of tea however, if you want a full complement of cogs on your cassette.

    Take a look at Nukeproof Generator rear hubs. They have proven themselves. One of these is what I would have picked if I wanted a full-cassette hub for a budget build. Basically they are generic Taiwanese cartridge bearing hubs, but Generators have 30 POE freehubs and are sealed better than most.
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  8. #58
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    What I want is a low drag quiet low maintenance hub rear with instant engagement.
    Maybe one with cartridge bearings, so I can swap them out easy instead of having to grease the bearings.
    I want to use a full 10 speed cassette and quick release mounts.
    Any ideas are welcome, I have another thread on this topic:
    Good and Quiet Hubs - Mtbr Forums

  9. #59
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    Quote Originally Posted by schristie11 View Post
    What I want is a low drag quiet low maintenance hub rear with instant engagement.
    Maybe one with cartridge bearings, so I can swap them out easy instead of having to grease the bearings.
    I want to use a full 10 speed cassette and quick release mounts.
    When I set out to find a hub with similar properties (except I looked for a singlespeed hub), I ended up with True Precision Poacher hub. To my knowledge, more silent and quick engaging hub simply doesn't exist. Shimano used to make silent clutch hubs for police bikes, but these had no support for disk brakes and are hard to find.

    True Precision also make hubs for full cassettes.

    I ran mine for almost a year without any issues. Then went to a fixed gear trials hub, because I also run Hammerschmidt, which has its own coasting mechanism.

    Downsides of TP hubs are weight, price and possibly vulnerability to water ingress. Because of this suspicion I only rode mine in fair weather and in sub freezing temperatures, so can't confirm this.

    I'm going to reuse my TP hub in a burly DJ/street build. Like the quietness and the engagement too much to part with it. Sadly, TP SS cogs are proprietary and cost $35 each, plus international shipping, and I need different gearing (32-16) than the one I used with HS (24-20).
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  10. #60
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    FLUSHING WITH OIL WILL NOT FIX A SLIPPING (FROM NEW) SHIMANO XT FREEHUB

    Well today I tried my bike on a 12 mile loop, with the new (200 miles ish of use) Shimano XT freehub fitted. I first flushed it with oil, as this freehub, taken from a spare wheel with a split rim, also suffered from the occasional slip from the very first ride, but I had just lived with it.
    Well all was well, until 3 miles from home, when pulling away from a traffic light stop, there was a now familiar loud cracking noise from the freehub, and the pedals slipped forwards 1 or 2 POEs.
    Enough is enough! Shimano have cost me a lot of money in the last couple of years with this problem.
    I will now have to buy 2 alternative new rear wheels / hubs for my 2 mountain bikes, that I cannot ride with any peace of mind with a problem like this.
    I will never choose to buy a Shimano rear hub again, as they have completely lost my confidence in their quality of freehubs. I must have gone through at least 5 in 2 years. While I lived with them they ruined many a ride. I spent hundreds on possibly unnecessary other drivetrain parts before knowing for sure that it was multiple freehub failures all along. Shimano must have known, and should have recalled the lot. What a disgrace!

  11. #61
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    Well after 3 months on my XT M775 wheels, the rear hub is not doing well. The free hub feels very loose and its making nasty crunching noise when it spin. I'm taking it to the shop tomorrow to hopefully get a new freehub under warranty.
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  12. #62
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    Turns out, the free hub on my XT hub cracked in half. And, according to the bike shop, Shimano won't warranty it either (despite the fact its 3 months old). Looks like I'll pay for a new free hub and just sell these XT wheels.

    I learned my lesson, I'm not buying a Shimano wheels/hubs again.
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  13. #63
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    It's a real shame. Whatever people used to think of Shimano's one time monopoly etc. at least you used to be able to count on reasonably reliable performance from their components. I just dont believe that's the case anymore. They have damaged their reputation in recent years, by producing short lived, throw away drivetrain components in particular. But these freehub body issues are totally unforgivable.
    They are just plain defective from new.

  14. #64
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    MBR Magazine agrees, XT freehub is faulty !

    In the October 2012 issue of MBR magazine, page 111, they are group testing all-mountain wheelsets.

    The Shimano XT Trail WH-788 £360 pair.

    Quote:-

    "One thing that's been disconcerting is from the very first ride the Shimano freehub body has cracked and slipped loudly."

    They give the Shimano wheels a score of 6 out of 10, the lowest on the test.

    While it was nice to see a magazine print an honest statement, about what the buyer faces these days (and has for some considerable time) when they buy any Shimano rear hub, I wish they had gone a lot further.
    A score of even 6 is still unjustifiable for a wheelset, where the rear hub is unrideable at best, and at worst is plain dangerous. Common sense dictates that a score of 0 is what is required here, much the same as you would expect to give to a handlebar which snapped off at the stem on a routine first test ride.
    This is not something that is safe to just live with, if you really think about it. You cant even change the freehub body at your own cost to rectify the problem either, as any replacement Shimano freehub body will invariably suffer the same slipping problem, right out of the box. At least that has been my experience with my last 3 rear wheels, and as many new separate rear hubs, bought specifically for the freehub bodies.

    The number of near misses, ruined rides, and hundreds of pounds spent on unnecessary drivetrain parts, thanks to Shimano exploiting me on this issue, makes my blood boil.

  15. #65
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    One word!

    S

    L

    X


    Nuff said!
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  16. #66
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    Quote Originally Posted by VTSession View Post
    Turns out, the free hub on my XT hub cracked in half. And, according to the bike shop, Shimano won't warranty it either (despite the fact its 3 months old). Looks like I'll pay for a new free hub and just sell these XT wheels.

    I learned my lesson, I'm not buying a Shimano wheels/hubs again.

    I wouldn't trust the LBS, I would send the hubs or just freehubs into shimano because shimano has never refused to warranty anything I have ever sent in. And yeah... many times the LBS's have said, no-way shimano won't fix that, and every time shimano has fixed it. For instant, last month I was riding a brand new moots pro that I just got done building up with all XTR drive components that I bought online at the beginning of this year, anyway, the "clamp pivot pin" on the my front derailleur snapped, so the front derailleur slid down into my crank, and that destroyed... my new XTR crank, my new XTR front derailleur, my new XTR chain, my new XTR rear wheel (the front derailleur and chain ripdded spokes right out my new stans notubes rim).So I had a total failure. Anyhow... I called shimano and they told me to take the bike to my LBS, and those guys were like, shimano won't cover any of this. Anyhow... to make a long story short... shimano replaced everything, they even had a new stans rear wheel built up for me, and they also gave me a new XTR wheel set for free. So like I said don't trust any LBS, send it directly into shimano because shimano will make it right.

  17. #67
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    New question here. 775 freehub disassembly?

    Well, another dead 775 freehub to report. About 9000 km on it, in wet & muddy conditions. Started to make funny noises and slip sometimes.


    Has anyone had success in picking one apart? I failed to do it, and here's the story.

    I ground a 21 mm hex socket into a 2-prong tool to fit the cup in Shimano freehubs. Used it on earlier freehubs (ones designed for steel axles), such as 756, all was fine every time. Tried it on a 775, had to create more torque than ever on a cup and finally a piece of cup cracked off from the stress. The cup itself did not move at all. Maybe there's threadlocker involved..

    I was also unpleasantly surprised to find the back rubber seal on freehub to be attached permanently to the body (as if welded), as opposed to it being removable on earlier models. This of course complicates any attempts to flush the freehub with solvents or oil, as mentioned above.


    To sum it up, Shimano seem to have went further in their policy of modular freehub replacement by taking steps to complicate freehub maintenance.


    What are your experiences guys?

    PS
    Please feel free to necropost here if you're from 2013 or later and still have experience with 775 freehubs.
    Last edited by J. Random Psycho; 12-05-2012 at 02:00 PM.
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  18. #68
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    I suggest heating the part in either boiling water or with a propane torch. If its some kind of loctite its plastic and almost all plastics gets a lot weaker at 100C. I have no experiences with shimano but I know what you're talking about. I have a new model ringle I tried to take apart but it refused. But i had no real interest in getting apart since its a **** taiwan hub anyway. But yeay they are hard to fully tear apart. Maybe i'll have a go at it in a few years. But I kinda doubt it.

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  19. #69
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    Yes, if I encounter another such freehub I'll use a heat gun on it, set to 125 Celsius. Perhaps it's indeed threadlocked.

    I also forgot to mention, that after the cup cracked I attempted the screwdriver and hammer method on the remaining slot. Cup didn't move either, and the pressure was such that the screwdriver end was taking some visible damage. But this desperate method has been successfully used on some earlier freehubs (not by me).
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  20. #70
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    Quote Originally Posted by J. Random Psycho View Post
    Avoid this one. The 756A is more like a glorified Alivio rear hub. Mush worse sealing than plain 756 and I suspect worse quality bearing races too. Entirely different innards than good old 756
    I've got an update on this.

    The rear hubs being now sold as FH-M756 at CRC come labeled FH-M756A, but they are no longer like glorified Alivio. Although the insides are still different from plain 756, they are not necessarily worse than these and I'd say certainly better than 756A design that I was talking about.

    There are now rubber contact seals at both sides. Cones look better polished. Locknuts are still hexagonal Alivio style, not round flanged 756 style; this feature can be used to identify plain 756 at first glance from either side. Another large external difference is how the non-drive side looks. On plain 756 it's a big, tall rubber cone. On "bad" (old) 756A it's a large diameter, low height black dome. And on "good" (new) 756A it's black and flat with a small diameter, low cone in the middle.

    My guess is that Shimano has recently merged 756 and 756A into this design.
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  21. #71
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    I just found this thread through a google search.
    I have a black 36h fh-m756 xt hub that I bought while working at a shop. probably came from hawley, but maybe qbp, maybe j&b; I don't remember.

    I had problems with the freewheel catching and acting like a fixie, but not enough to cause derailleur damage, just enough to be a pain.

    I figured I too had a damaged freehub, as a few days before the non-freewheeling started I had a "chain-slip" on a steep climb; I figured it was related to a worn derailleur and crappy housing, but now I think I know what happened.

    I pulled out the axle and went to remove the freehub body fixing bolt with a 10mm allen wrench and the bolt just fell out. I worked the freehub off the body and immediately noticed that the teeth that keep the freehub from spinning on the hub were severely damaged, as though the body fixing bolt had loosened and the whole freehub had spun around with respect to the hub body, chewing off about a 1/4 of the teeth from the hub body (freehub body looks and spins fine when taken off the hub). the threads in the hub body where the fixing bolt goes in were a bit damaged (but really hard to see down in there) but I was able to get the bolt to thread on. There were only 8 of 9 bearings on the drive side, I suspect this allowed the freehub to wobble off of the teeth more easily.

    I've never heard of a freehub body fixing bolt coming loose, let alone backing all of the way out. the hub is about 2 yrs old and I do ride a lot. The bearings came out quite clean except the missing one... about a year ago I had to retighten the drive side locknut, but I only loosened the axle, never removed it, so I know those bearings were absent from the factory.

    Even if I warranty this succesfully, I'll still have to rebuild my wheel, and the rim really isn't in good enough shape to do that. the ideal course of events would have been for this wheel to become an eventual backup.

    And I thought I was buying a reliable hub.

    edit: freehub is cracked!

    here are full-size pics: https://plus.google.com/photos/10034...LCm7Z3Z5d_UxAE








  22. #72
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    It doesn't happen often but yes, freehub bolts can self-unwind. Because of this I not only check drive side locknut tightness on Shimano hubs (including new ones), but also the freehub bolt.
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  23. #73
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    Quote Originally Posted by PretendGentleman View Post
    I pulled out the axle and went to remove the freehub body fixing bolt with a 10mm allen wrench and the bolt just fell out...I've never heard of a freehub body fixing bolt coming loose, let alone backing all of the way out...And I thought I was buying a reliable hub.

    edit: freehub is cracked!
    And there's your answer. Cracked freehub body loosened the bolt slightly. Since it was no longer locked in place, it walked out. The hub itself was probably of adequate quality, the freehub probably had a small defect. Shimano should warranty that hub, and if you don't need the replacement hub for a wheel rebuild...ebay it?

  24. #74
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    Cracked FH body

    Was a replacement from August. I'd had issues with the hub loosening (I think the axles are too long to get a proper adjustment) so a friend's shop had all the internals sent out and replaced them for me including a new FB. Last weekend I hear a nasty noise out back but the FH wasn't slipping. I had ANOTHER spare lying around from a friend who said I'd need it one day. Just pulled it off and guesss what? Cracked. Cassette was torqued to spec on install so who knows...
    Attached Thumbnails Attached Thumbnails Shimano XT M775 Wheelset Freehub fails ?-img_3126.jpg  

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  25. #75
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    Quote Originally Posted by sjordan72 View Post
    Was a replacement from August. I'd had issues with the hub loosening (I think the axles are too long to get a proper adjustment) so a friend's shop had all the internals sent out and replaced them for me including a new FB. Last weekend I hear a nasty noise out back but the FH wasn't slipping. I had ANOTHER spare lying around from a friend who said I'd need it one day. Just pulled it off and guesss what? Cracked. Cassette was torqued to spec on install so who knows...
    I have to wonder if these cracked freehub bodies are coming from Singapore or Malaysia. It seems Shimano's parts were much higher quality when manufactured in Japan, even if the designs of those Japanese parts were dated.

  26. #76
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    I had the same crack failure (fully on one side and halfway on the other) after 1.5 years of light use on my replacement freehub after the original seized. I'm surprised that the cassette lock ring would still tighten after I found it (yes, I did another ride on the cracked body and it held up - who knows how long it's been cracked!)

    Going to buy a replacement and sell the XT wheel.

  27. #77
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    i wish i had found this topic eralier

    around 1000km xc on it.



    sh*t.

  28. #78
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    There is more than one ratchet model used on 9sp XT free hubs. Enjoy:

    M750 Y-3BC-98030
    M752 Y-3BD-98010
    M755 Y-3BC-98010
    M756 Y-3BD-98010
    M756A Y-3SW-98060
    M760 Y-3CO-98010
    M765 Y-3CO-98010
    M770 Y-3CZ-98050
    M775 Y-3CZ-98050
    M785 Y-3CZ-98050
    M788 Y-3TH-98060
    T660 Y-3D6-98050
    T670 Y-3D6-98050
    T675 Y-3D6-98050
    T780 Y-3CZ-98050

    The Y-3CZ-98050 is the notorious model used with the 12mm aluminum axle. The dog-ears on the pawls snap off and turn into shrapnel that gets jammed in place. Your bike becomes a fixie/der destroyer.

    Other ratchets use pawls without dog-ears. There is a single spring down the center of the pawl (see Phil Wood) rather than two on the dog ears. They seem to fail by freewheeling due to wear or body cracking.

    The Y-3D6-98050 is on a 10mm steel axle with the same fixing bolt as the Y-3SW-98060. It may or may not have the same problem as the Y-3CZ-98050.

    The Y-3SW-98060 on the 756A is the same as that on the M529. This is the high flange hub Shimano rates for 36t cogs and 29ers. I would guess the M756A, with its high flanges, could pass the test as well.

    As a side note, the 36t rated low-mid flange M629 uses the Y-3D3-98080. This 32 point free hub is the same found on the SLX M675. The M675 and M629 seem to be the same save the hubshell finish/graphics.

    What I would love to see is postings noting the exact ratchet part number that failed. Just to get an idea of what is really going on.

  29. #79
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    So it's the same part# for 775 and 785 hubs. Maybe Shimano have "hidden" revisions not reflected in those designations? Otherwise 785 inherits all the problems of 775.
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  30. #80
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    Quote Originally Posted by kemal View Post
    What I would love to see is postings noting the exact ratchet part number that failed. Just to get an idea of what is really going on.
    I dont't know the ratchet's part number but i was running the FH-M785 bought in early 2013 from bike-components.de

    I sent the wheel in January 2014 to Shimano and they replaced the freehub on warranty. Unfotunately the hub turned into crap after one wet ride so i decided to switch to SLX m665.

    My fh-m785 after a wet ride:
    Shimano XT M775 Wheelset Freehub fails ?-img_2884.jpg
    Shimano XT M775 Wheelset Freehub fails ?-img_2885.jpg
    Shimano XT M775 Wheelset Freehub fails ?-img_2880.jpg

  31. #81
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    that's contaminated grease, but that rust wouldn't develop in one ride, that's a long-term issue....

  32. #82
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    Quote Originally Posted by abuwz View Post
    Unfotunately the hub turned into crap after one wet ride so i decided to switch to SLX m665.

    It probably took more than one ride to develop the pitting on that cone too, holy schmoly!

  33. #83
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    I replaced my xt with a dt swiss 350 hub about 800 miles ago. I like the 18 point engagement. It's an expensive hub, 3-4 times the xt's price. I'll know for sure if it outlasts an xt in another 3 months. I even broke the supposedly stronger 36t compatible slx freehub I replaced my xt freehub with. No shimano hub has lasted more than 6 mo on my mtb.

  34. #84
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    Such cone damage is usually due to misadjustment.

    With that said, my rear hubs of choice these days are Nukeproof Generator and True Precision, with strong preference to the latter even though it's like 200 g heavier.
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  35. #85
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    Shimano XT M775 Wheelset Freehub fails ?

    Quote Originally Posted by J. Random Psycho View Post
    Such cone damage is usually due to misadjustment.

    With that said, my rear hubs of choice these days are Nukeproof Generator and True Precision, with strong preference to the latter even though it's like 200 g heavier.
    Misadjustment and/or a hub that would not hold the adjustment. I had the later with my hub. Could only find a replacement cone as part of a complete axle assembly, for more than half the price I paid for the whole hub. Since the FH had previously failed, I replaced the hub with a different brand. The XT went straight into the recycle bin.
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  36. #86
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    I think the bulk of the failures on the Y3CZ98050 have been with the pawls/dog-ears. Yours is a cracked body. Did the pawls fail also, jamming the ratchet and perhaps causing the body to crack?

    Quote Originally Posted by abuwz View Post
    I dont't know the ratchet's part number but i was running the FH-M785 bought in early 2013 from bike-components.de

    I sent the wheel in January 2014 to Shimano and they replaced the freehub on warranty. Unfotunately the hub turned into crap after one wet ride so i decided to switch to SLX m665.

    My fh-m785 after a wet ride:
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    This looks like a combination of grease failure (emulsification) and over tightening. It looks like false brinelling.

    These hubs use a threaded aluminum axle. Is it possible the end caps can not be tightened enough to prevent the cones from self-tightening? From 30+ years of rebuilding steel axle hubs I know I can tighten them enough to keep the cones in place. The SLX should be axle of steel.

  37. #87
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    Quote Originally Posted by abuwz View Post
    I dont't know the ratchet's part number but i was running the FH-M785 bought in early 2013 from bike-components.de

    I sent the wheel in January 2014 to Shimano and they replaced the freehub on warranty. Unfotunately the hub turned into crap after one wet ride so i decided to switch to SLX m665.

    My fh-m785 after a wet ride:
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    Lookin good there! I used to park and ride my commuter out in the rain for several years. I had one of the cheapest hubs, non series crapola. and after 4 years it was like new inside. I cracked mine open at least once a year though for a full cleaning and regreasing. I used solvents and 556 in the mechanism.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.

    Quote Originally Posted by iheartbicycles View Post
    Specialized sucks ass.

  38. #88
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    I called Shimano North America. Asked about the Y-3CZ-98050 free hub body used on the M770, M775/6, M785 and T780. The part was updated in the 12/2013-1/2014 timeframe.

    Let's hope this is the end of the bad metallurgy.

  39. #89
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    I apologize if this has been addressed already. I just blew out my freehub body on my shimano fh-m475 for the second time. I know they aren't the best hubs out there at all but at the time I can't afford a new wheel set or hubs. Do any of you know if any other freehub bodies are interchangeable with this one? I can just buy the same one again but I would think the slx, xt or xtr would be stronger than what is on there.

  40. #90
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    Shimano XT M775 Wheelset Freehub fails ?

    Quote Originally Posted by kemal View Post
    I think the bulk of the failures on the Y3CZ98050 have been with the pawls/dog-ears. Yours is a cracked body. Did the pawls fail also, jamming the ratchet and perhaps causing the body to crack?



    This looks like a combination of grease failure (emulsification) and over tightening. It looks like false brinelling.

    These hubs use a threaded aluminum axle. Is it possible the end caps can not be tightened enough to prevent the cones from self-tightening? From 30+ years of rebuilding steel axle hubs I know I can tighten them enough to keep the cones in place. The SLX should be axle of steel.
    The aluminum axle could be the issue. The threads can deform more easily allowing the adjustment to change (tighten or loosen).
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  41. #91
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    I've had a similar issue with a Deore freehub body developing cracks and falling apart. Both times the freehub body was less than 3 months old (i'd estimate less than 100 hours riding). The photo below is the remnants of the freehub body after the first failure (heard a popping sound and the freehub locked up so that I couldn't pedal, cue a 2 hour walk home).

    Shimano XT M775 Wheelset Freehub fails ?-freehub-failure.jpg

    The first time it was warrantied no questions asked as the wheelset was on a new bike, but this time I'm nowhere near a dealer (or even a bikeshop for that matter) that I could take the wheel to so it could be replaced through warranty. The second time it happened was a few days ago, and exactly the same thing happened again. I'm probably going to replace the whole wheel, as I just don't trust the shimano freehubs given my experience on them. Incredibly disappointed.

  42. #92
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    Purchased new bike 2 months ago with deore hubs. Second freehub in that timespan is already sticking. Highly dissapointed and discouraged. Local lbs won't sell or service this hub. I'm hoping Shimano will warranty me with an xtr freehub to make this mess right.

  43. #93
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    Dang 802. Sorry. Last time I tried to warranty one as a consumer they asked me if I had ever broken spokes. I said yes. They asked if I had completely detensioned the wheel when I replaced the spokes.

    Seriously?

    If anything I think overtorquing the cassette lock ring may be to blame in some of these failures. Now that I am working as a shop owner mechanic I use a torque wrench when I install cassettes (and most other drive train parts) and I find that the 40 Nm spec is a lot lower than we often beast these things on at.
    Obviously, you're not a golfer.

  44. #94
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    Interesting thought about the torque wrench. This particular bike came from a shop outside of town, not the one I mentioned. So I took it there (where it was built) to have the second freehub installed. He was wrenching on it HARD. I've previously had a hell of a time undoing other bolts. Also, there is a plastic guard between my wheel and cassette which is bent (could've been a rock, who knows). And, I've been really struggling to keep my derailleurs aligned. Could it all be related? Who knows. I'm trying to learn my way around the bike so I've given this all a lot of thought and something just isn't adding up--maybe you're onto it.

  45. #95
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    Quote Originally Posted by 802spokestoke View Post
    Interesting thought about the torque wrench. This particular bike came from a shop outside of town, not the one I mentioned. So I took it there (where it was built) to have the second freehub installed. He was wrenching on it HARD. I've previously had a hell of a time undoing other bolts. Also, there is a plastic guard between my wheel and cassette which is bent (could've been a rock, who knows). And, I've been really struggling to keep my derailleurs aligned. Could it all be related? Who knows. I'm trying to learn my way around the bike so I've given this all a lot of thought and something just isn't adding up--maybe you're onto it.

    I seriously doubt overtorquing the cassette lockring is breaking freehub bodies. Also, it sounds like you might be equating the lockring with the freehub's anchor bolt (I'm sure there's a better name for it). The freehub anchor bolt should be damn tight to keep it from wandering loose. The cassette lockring doesn't seem to matter a whole lot for steel freehub bodies, just as long as it's fairly tight.

    It seems pretty clear to me that inferior materials/construction is the problem, not user error. Shimano is cutting corners with these freehubs and it works fine for 95+% of riders, which may be fine with shimano.

  46. #96
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    Quote Originally Posted by 802spokestoke View Post
    Purchased new bike 2 months ago with deore hubs. Second freehub in that timespan is already sticking. Highly dissapointed and discouraged. Local lbs won't sell or service this hub. I'm hoping Shimano will warranty me with an xtr freehub to make this mess right.
    Your LBS needs to step up. Replacing an FH body should take them 15 minutes.

    Which model of Deore are you running? If it is an FH-M615, which should have a 98060 FHB. This body is used on the M529, which is rated for 29er/hi torque 36t cog.

    Shimano will send another body. The 98060 is a $19 part. An XTR body is in excess of $160. Best of luck getting the whole XTR hub.

  47. #97
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    yeah, warranty replacement does not equal "free upgrade"

  48. #98
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    I was thinking just the xtr freehub (If it's even compatible, I'm not sure). I really don't expect them to send one. But I will be politely pressing the issue that this is not acceptable for a 5 inch travel bike (That would be taken up with the bike manufacturer). The LBS that won't fix it has told me they will have nothing to do with shimano hubs. I didn't buy the bike from them so I'm not really concerned, rather I was showing the reputation that these hubs have made for themselves.
    The shop I bought it from is over an hour away--but that's my problem.
    The hub is an FHM-618. I cannot find a part number on the freehub on the workbench.
    I should probably just try and get some money for the wheelset and upgrade, but that's alot of lost riding time.

  49. #99
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    Shop owner was awesome. He was understanding and is willingly taking it up with shimano for me. Fingers crossed.

  50. #100
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    Props to shimano for doing right. Free upgrade in the mail. Sounds like shop owner had to work some magic but none the less.

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