• 01-27-2010
    Nick_M2R
    The Complete Fox DHX 3/4/5 Service Thread
    Hi all :thumbsup:

    Here is the 4th Version of my Fox DHX 3/4/5 Service Guide

    It shows you how to completely service (about 98%) your DHX, including the rebound and propedal assemblies. Servicing the rebound assembly will require careful use of a propane torch, so before commencing work on your shock, be sure you uderstand what you are doing by first reading the method in which to use the propane torch.

    Make sure you download and read through the tutorial carefully before commencing work on your shock

    ================================================== ===============

    Shock Models Supported;
    2005 - 2009 Fox DHX 3/4/5 Coils
    2010 Fox DHX 3/4

    ================================================== ===============

    NOTE: CERTAIN DHX 5 THAT CAME STOCK ON SPECIALIZED SX TRAILS HAVE UNADJUSTABLE BOOST VALVES, MEANING THERE IS NO AIR VALVE FOR YOU TO ADJUST, INSTEAD THEY ARE FACTORY CHARGED WITH NITROGEN

    DO NOT ATTEMPT TO SERVICE THESE SHOCKS!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    ================================================== ===============
    Download Links:
    ( I know the hosting sites arnt liked by many people, but sorry it will have to do for now :D )

    Guide:
    http://www.mediafire.com/?lotejczmzz0

    ================================================== ===============

    Enjoy boys and girls

    Also if you use this guide please report your success, also CONSTRUCTIVE critisim is welcomed, oh, and do not ***** about how i used a shifting wrench, its all i had, use a spanner if you wish

    Cheers!
  • 02-01-2010
    tuumbaq
    Thanks for the guide Nick, It really helped me figuring out what was wrong with my shock !
  • 03-15-2010
    croft92
    For start I would like to thank you for the guide NICK...I`ve got a problem with my shock FOX DHX 5.0 2008 and i can`t figure out what`s wrong..I hear a sound like a knock inside the shock ....I always ride with 125 psi in the air chamber so the air its not the problem .. For example my shock become very strong at compression when i rotate the rebound knob clockwise (10-15 click) and the sound is very strong and afect the performance of the shock ....The same thing happen when i am activating the propedal , but the sound seems to double (2 knocks at one time )....I am waitng an answer from you NICK ....THX ..great job
  • 03-15-2010
    Wil109
    Quote:

    Originally Posted by croft92
    The same thing happen when i am activating the propedal , but the sound seems to double (2 knocks at one time )....I am waitng an answer from you NICK ....THX ..great job

    You might have suffered the same issue as me, see this link, http://forums.mtbr.com/shocks-suspension/fox-dhx-3-4-5-coil-rebuild-thread-538515.html. I don't think that I snugged the shim stack assembly on tight enough.

    Don't ride it, open the shock back up and check it out.

    Wil
  • 03-15-2010
    Bikinfoolferlife
    Thanks for the guide! Haven't used it yet, but plan to soon...

    No way to actually get the o-ring sizes from you, is there? Would be great to be able to order them and have them on hand at the start. Don't know of any place I could go to get them sized exactly either. Anyone have a good spot in the San Francisco area? Peninsula preferably...

    PS Just saw cowpat's list in the thread wil109 posted...
  • 03-15-2010
    croft92
    its not the piston bolt :( i am very sad ..dont know what to do ....help me guys with some ideas
  • 03-24-2010
    FreeRideABullit
    Hey Nick, Thanks for all the research and development on this very comprehensive guide!

    I ran into a bit of a snag with my rebuild,

    When I go to take the lockring off of the piston assembly the entire cylinder starts to loosen from the black carriage instead of the lockring itself. I've tried putting it very tightly in a vice among other more barbaric things and was wondering if you had any advice for this scenario.

    Thanks,

    Dave
  • 03-24-2010
    Nick_M2R
    Quote:

    Originally Posted by croft92
    its not the piston bolt :( i am very sad ..dont know what to do ....help me guys with some ideas

    Ok sorry guys for leaving this thread dead for awhile, have been mega busy starting my new life at college and Uni

    EDIT: ok just checked and read that you dont got a 05 model DHX
    Ill be honest, im quite stumped at what could be causing this :???:

    Hmm...:idea:

    Well make sure you double check that you havent overtightened the piston bolt, as this is the cause of the problem 85% of the time. Failing that, did you remove the PP assembly? If you did are you sure that you put all the springs and such back together properly?, and also check to make sure the snap ring is resting in its groove properly

    Hope this helps, let us know how it goes!
  • 03-24-2010
    Nick_M2R
    Quote:

    Originally Posted by FreeRideABullit
    Hey Nick, Thanks for all the research and development on this very comprehensive guide!

    I ran into a bit of a snag with my rebuild,

    When I go to take the lockring off of the piston assembly the entire cylinder starts to loosen from the black carriage instead of the lockring itself. I've tried putting it very tightly in a vice among other more barbaric things and was wondering if you had any advice for this scenario.

    Thanks,

    Dave

    Hi Dave

    Now when you say lockring, do you mean the snap ring inside the Resi that holds the PP assembly in, or are we talking about the piston bolt? the thing that holds the piston and shims on?

    If its the piston bolt thats stuck and causing the shaft to unthread from the rebound housing eyelet (the black thing at the bottom of the shaft in which the red rebound adjust resides) then to get in undone, first clamp the shaft as tight (being careful not to damage the shaft finish) as you can into wooden clamps as is shown in my guide, then use a propane torch to GENTLY heat the top of the shaft underneath the piston (where the tiny hole is) make sure you heat it evenly, and only until its hot to touch. Now the bolt should come of much easier now, if not, make sure its firmly clamped and give it a tiny bit more heat.

    Hope this helps, let us know how it goes! :thumbsup:
  • 03-24-2010
    FreeRideABullit
    to clarify i'm talking about step 4. in the guide. the entire cylinder is coming unthreaded from the black turn around instead of just the piston cap. so in short i can't get the piston out the cylinder. hopefully you know a trick for me!
  • 03-24-2010
    Nick_M2R
    Ahh.. righto im with ya now!

    Righto, so the entire cylinder is unwinding?

    Well in that case, my fix would be the same as what i said above.
    Make some shaft clamps outta some hardwood off cuts and clamp the entire cylinder firmly into the vice (with the clamps of course). Just be careful not to crush it.

    Then again, using a propane torch, heat up the cylinder where the shaft housing (the black thing in which the shaft goes into) screws into it, heat around that area evenly until it is hot to touch, then making sure the cylinder is firmly clamped, undo the shaft housing. This should get it undone, Fox dont loctite it, but it gets torqued fairly high, mine was tight to undo the first time as well, but the propane torch fixed that.

    One more thing, seeing as you said that the cylinder was unscrewing from the main body, make sure that when you have removed the piston and the shaft that you flip the thing around, again clamp it, and tighten the main housing (the black bridge that connects the main cylinder to the resi. You will have to use a breaker bar and insert it through the mount hardware to get enough leverage to tighten it , as hand tight wont be enough.

    Hope this helps, let us know how it goes and if you got anymore questions, dont hesitate to ask!
  • 03-24-2010
    AaronJG
    this guide is wicked, its in my book of what can i try not to screw up on my bike lol, thanks 4 putting ur time into this and hope u make other guides foe all of us eager learners.:thumbsup: :thumbsup: :D
  • 03-25-2010
    Nick_M2R
    Quote:

    Originally Posted by AaronJG
    this guide is wicked, its in my book of what can i try not to screw up on my bike lol, thanks 4 putting ur time into this and hope u make other guides foe all of us eager learners.:thumbsup: :thumbsup: :D

    No probs mate! :thumbsup:
    Sharing info like this is what makes it all worth while!

    Dont worry, got a few more guide up my sleeve, just been mega slack about em lately because ive just started adapting to my new life at uni and college, fun times!

    But for now, if you wanna see some of my other guides, check my signature for links on how to service the Marzocchi ATA cart amd how to tune the Mission Control Shimstack!:thumbsup:
  • 03-26-2010
    Nick_M2R
    A little update guys, have been poking round through the files of the fox service site that used to be uploaded here, and have stumbled across this IFP Depth chart

    As you can see, the depths differ for the DHX 3/4 compared to the 5, which makes sense because the increased IFP depth figures for the 5 are compensating for the bottom out adjuster (which is simply a screwable plug that increases or decrease the volume of the boost valve chamber.)

    Here it is, will update the one in the guide soon....
    ------------------------------------------------
    DHX 5.0 Coil IFP Depth:
    ------------------------------------------------

    I2I - Stroke: Depth (inches):

    7.50 X 2.00 1.250
    7.875 X 2.00 1.250
    7.875 X 2.25 1.300
    8.500 X 2.500 1.350
    8.750 X 2.500 1.350
    9.500 X 3.00 1.480

    ------------------------------------------------
    DHX 3.0/4.0 IFP Depth:
    ------------------------------------------------

    I2I - Stroke: Depth (inches):

    7.50 X 2.00 1.150
    7.875 X 2.00 1.150
    7.875 X 2.25 1.200
    8.50 X 2.500 1.250
    8.75 X 2.500 1.250
    8.75 X 2.750 1.250
    9.00 X 2.500 1.250
    9.00 X 2.750 1.375
  • 03-26-2010
    ramonet
    Hello someone make a service change oils in a fox float air shock? Is it necessary to add nitrogen later or only refill even above(up) without air bubbles?
    thanks a lot, excuse for my english.
  • 03-29-2010
    Blofeld
    IFP Tuning?
    Quote:

    Originally Posted by Nick_M2R
    DHX 3.0/4.0 IFP Depth:
    ------------------------------------------------

    I2I - Stroke: Depth (inches):

    7.50 X 2.00 1.150
    7.875 X 2.00 1.150
    7.875 X 2.25 1.200
    8.50 X 2.500 1.250
    8.75 X 2.500 1.250
    8.75 X 2.750 1.250
    9.00 X 2.500 1.250
    9.00 X 2.750 1.375

    Is it possible to tune the bottom out response of a DHX 3.0/4.0 by adjusting the IFP depth? If so, what sort of changes will result from raising or lowering the piston?

    Thanks for creating a very useful guide! :thumbsup:
  • 03-29-2010
    Nick_M2R
    Increasing the depth will increase the volume of the boost valve, making the shock more linear.
    Decreasing the depth will decrease the volume of the boost valve, making the shock more progressive

    But be warned, you have to make sure you dont push it to deep (causing it to hit the top of the resi, or to shallow (will knock on the boost valve cap)
  • 04-07-2010
    cesalec
    It is a great guide, though I have a completely newbie, mechanical retarded ingenieur, a term glosary could be great , even a graphic glossary of all the parts, so we all know (those who we have no idea) understand also completely. =):thumbsup:
  • 04-07-2010
    cesalec
    Quote:

    Originally Posted by cesalec
    ... I have a completely newbie

    I meant: though I as a complete newbie....
  • 04-07-2010
    Nick_M2R
    hi mate
    what are the terms you'd like to know, ill probably work on a glossary i my spare time

    For know, the terms that i can think of are

    IFP = Internal floating piston
    BO = Bottom out adjust
    PP = Propedal
  • 04-07-2010
    Blofeld
    A list of the small parts could be useful, especially if they could be cross referenced with Fox part numbers to make replacing things easier. If anything, a list of the o-ring sizes would be great to have in the guide to avoid having to run to the hardware store midway through the job.

    In terms of the major components, I thought the photos did a good job showing what was what. It might be interesting to know what is interchangeable between different shock models and sizes, but that's more of a personal curiosity.
  • 04-07-2010
    cesalec
    maybe guides for complete dummys who have absolutely no idea.. would actually be great, lets say, in the engineering world, most of the procurement specifications are done in a way a kid could understand them. At least thats they it should be to avoid daylong meetings with a bunch of engineers who cannot read engineering specifications :P

    I was trying to set my Fox DHX 4.0 on my 2008 Reign 0, Fox manulas were brief, confusing and useless...
  • 04-12-2010
    kman07
    Does anybody know the o-rings sizes on a DHX 5.0 and the stock shim stack?
  • 04-12-2010
    Nick_M2R
    Stock shim stack differs from year to year, i only know the stock shim stack for a 09 DHX 5

    With the o-rings, its best to take the old ones to a supply store and have them sized for new ones, ensures you get the correct size ones

    Main reason i dont bother with measuring and posting the sizes is because i dont got a good set calipers, and the conversion between metric and imperial is annoying (when are you americans gonna see the light and swap to metric!!!!)
  • 04-12-2010
    kman07
    I found the o-ring sizes, I have already bought them but I just wanted to doubt check that they weren't metric. I have a 2009 DHX 5.0 so I would love it if you could post up the shim stack.
  • 04-13-2010
    Wil109
    Does anyone have a piccie of a 2008 DHX 4.0 Coil Shocks stock shim stack (say that quickly after 5 beers).

    I goosed my shock and the shim stack came apart. Since putting in back together several different ways I can't seem to get the rebound quite right...... anyone any tips.... at all..... please.....

    All the best and thanks for any replies (helpful or constructive ones tho :thumbsup:)
  • 04-13-2010
    Nick_M2R
    1 Attachment(s)
    Quote:

    Originally Posted by kman07
    I found the o-ring sizes, I have already bought them but I just wanted to doubt check that they weren't metric. I have a 2009 DHX 5.0 so I would love it if you could post up the shim stack.

    Righto, here is a pic of the stock shim stack on my 09 DHX, the far left washer is the black steel back plate, between that and the piston is the compression stack, then on the right of the piston is the rebound stack, followed by the piston bolt, make sure that when reassemble the stack, that the flat side of the piston faces down

    Hope it helps!
  • 04-13-2010
    Nick_M2R
    Quote:

    Originally Posted by Wil109
    Does anyone have a piccie of a 2008 DHX 4.0 Coil Shocks stock shim stack (say that quickly after 5 beers).

    I goosed my shock and the shim stack came apart. Since putting in back together several different ways I can't seem to get the rebound quite right...... anyone any tips.... at all..... please.....

    All the best and thanks for any replies (helpful or constructive ones tho :thumbsup:)

    Wont be able to give you any promises, but ill have a poke around and see if i can come up with anything :thumbsup:
  • 04-13-2010
    kman07
    Well, There must be different tunes of the DHX... This site is different than yours http://ukmb.net/forum/index.php?topic=37675.0;wap2

    And mine is different than both.

    Mine goes

    Washer

    10.30x0.38mm
    15.25x0.25mm
    22.85x0.38mm
    22.85x0.38mm
    22.85x0.38mm COMPRESSION
    12.70x0.25mm
    20.25x0.25mm
    22.85x0.25mm

    Piston


    17.85x0.38mm
    17.85x0.38mm
    17.85x0.38mm
    15.25x0.25mm
    15.25x0.25mm REBOUND
    12.70x0.25mm
    12.70x0.25mm
    10.30x0.38mm

    Small Washer
  • 04-13-2010
    kman07
    Nick_M2R What are the dimensions of your shock?
  • 04-13-2010
    Nick_M2R
    Mine is 8.5 x 2.5, i purchased mine on ebay from a guy who got them direct from fox, and i believe it may have been tuned for the leverage ratio of my stinky, 2.8:1, this may explain the difference from yours, i have heard of the stack differing across the board for the shock
  • 04-13-2010
    Nick_M2R
    Also, i wouldnt trust some parts of the repair instructions on that site, threadlocking the piston bolt is a bad idea, if you get threadlock on the shims, which is quite easy to do, you will threadlock your shims together, which will damage you shock....
  • 04-13-2010
    kman07
    It may just have to do with length too, mine is a 9.5x3.0 I might shoot push and fox an email.

    Yeah im not using those instructions I was just referring to the shim stack.
  • 04-13-2010
    Nick_M2R
    No probs mate, sorry i couldnt be of more help, let us know how it goes!
  • 04-14-2010
    kman07
    Turns out there are multiple tunes and they vary with length. I've contacted a local suspension tuner for a quick recommendation and I'm about to try it out.

    One more thing, the IFP depth.. Is it measured from the flat part of the piston or the little nipple thing?
  • 04-14-2010
    Nick_M2R
    Quote:

    Originally Posted by kman07
    Turns out there are multiple tunes and they vary with length. I've contacted a local suspension tuner for a quick recommendation and I'm about to try it out.

    One more thing, the IFP depth.. Is it measured from the flat part of the piston or the little nipple thing?

    Flats of the IFP
  • 04-22-2010
    arekieh
    k quick question,
    How can i tell if my shock needs a rebuild? I just bought my bike from a guy in the states and its in much worse condition than he said it was :( (he still hasnt replied to my emails).

    Anyways, the shock feels fine but the propedal adjustment and all the nobs feel super gritty. I thought rebuilding would be pretty easy but from the looks of it its a pretty big job. Im fine with doing it but i dont want to do it needlessly.
  • 04-22-2010
    Nick_M2R
    Quote:

    Originally Posted by arekieh
    k quick question,
    How can i tell if my shock needs a rebuild? I just bought my bike from a guy in the states and its in much worse condition than he said it was :( (he still hasnt replied to my emails).

    Anyways, the shock feels fine but the propedal adjustment and all the nobs feel super gritty. I thought rebuilding would be pretty easy but from the looks of it its a pretty big job. Im fine with doing it but i dont want to do it needlessly.

    If only the adjustment knobs are gritty, then simple (for the propedal) remove the screw that is onto of the propedal knob, remove the adjuster (watch out for the detent balls) clean all the dirt out, regrease the balls and their races, then reassemble, same goes for the Bottom out adjuster. Loosen the grub screws on the side of the adjuster, remove it, clean, lightly grease, then reassemble.

    A shock generally needs to be rebuilt or rebleed when you hear alot of squelching when cycling the shock, which means air has mixed itself with the oil
  • 04-22-2010
    arekieh
    ahh ok makes sense. thanks alot.

    Your guide is awesome btw. definitely saving it
  • 04-22-2010
    Nick_M2R
    Quote:

    Originally Posted by arekieh
    ahh ok makes sense. thanks alot.

    Your guide is awesome btw. definitely saving it

    Cheers mate!
    Glad you find it helpful :thumbsup:
  • 06-08-2010
    lukesheffield
    Hi

    The guide is really really good and have dissasembled the shock and rebuilt it due to an ongoing leak behind the pro pedal adjuster, I thought all was sorted..... but unfortuntely the pro pedal is back to leaking again......

    On dissasembling the pro-pedal, I found some more bits than were not in the photo from enemy1 (I should have taken photos.... doh)....anyway there was a hex shaft that comes in from the adjuster, then there was a small piece threaded on the outside with a hex cut out in the middle where the shaft of the adjuster fits, this then fitted in via a left hand thread, into a slightly larger piece which had threads both inside and outside..... I replaced an additional o-ring where the adjuster hex shaft part comes into the housing..... but its still leaking..... I tried getting the reservior off but its on bloody tight and I didnt want to damage it...... will dissasemble the whole thing and try more heating!! my wooden blocks have cracked so probably need to get some better wood......

    Do you have any more propedal diagrams / photos...... I put these things back in the order 'I thought' they came out ..... just hope they are in right!! Any tips on getting reservoir housing off.

    Ps is there any way of working out the year of the shock

    Thanks
  • 06-09-2010
    lukesheffield
  • 06-09-2010
    Nick_M2R
    No probs luke
    Glad to hear you like the guide
    With regards to the extra propedal bits, i assume your talking about the internals of the DHX adjuster? For my next update, i plan to simply drill out a hex key so that i can remove the adjuster and get to that propedal o-ring

    With regards to removing the chamber, all i can recommend is that you use a high quality hardwood for the clamps (I used some of cuts of Australian river redgum) Softwood wont do it. Then just try giving it some more heat, but be careful!

    Let us know how it goes, and if you find any other things inside the DHX let us know!
    Cheers!
  • 06-10-2010
    lukesheffield
    Right its stopped leaking from the pro-pedal..... The pro pedal adjuster holder that is tightnened down using the custom 8mm allen key thing had come loose and wasnt sitting against the o ring, which was slightly damaged.

    I tried drilling and dremeling an 8mm allen key but its way too hard (need a crap soft poundland set). So instead I got a M10 bolt and ground the threads down to 8mm hex then drilled that out, much easier but its a bit soft. Did the job tho. Found after first fitting the pro pedal needs to be full in as otherwise when doing up the holding piece the adjsuter locks out on the adjuster shaft.

    Thanks again for the guide.
  • 06-10-2010
    PissedOffCil
    Hey, I used your guide to maintain my DHX3 and all went good (apart from having a hard time unscrewing the main body) so thanks a lot for putting this together!
  • 07-07-2010
    dukenz
    N2 charged DHX - convert to air charged?
    Nick,

    Great step by step guide, thanks. My DHX 5 stripped is down apart from rebound and shaft - more heating and hardwood block I suspect. :madmax:

    A question, you mentioned some DHX (4?) that were fitted to Spec'd that didnt have the air valve for bottom out adjustment - these were nitrogen charged and blank grub screwed off.

    My question is, if you take the nylon blank out of the allen key hitting in the grub screw, is it not simply a matter of gently unscrewing this to release the nitrogen charge behind it ie before it flies out the charge will release? Then you can service as normal? If you then replace the grub screw with the normal air valve, that effectively makes it a DHX 4.

    Just a thought.

    Also more than happy to help you with glossary project if you want. How about an exploded diagram with labels (DHX5 coil) with O ring sizes?

    Cheers
    Duncan
  • 07-21-2010
    mtnbikinggolfer
    i was just wondering if i can still use this on my '10 totem solo air. my problem isnt bottoming out too much, its that the last inch of my rebound hardly ever is used. it doesn't have a floodgate so i believe its the DH one. sorry i dont completely understand this yet but could i just put on some slightly smaller shims?
  • 07-22-2010
    Nick_M2R
    Quote:

    Originally Posted by mtnbikinggolfer
    i was just wondering if i can still use this on my '10 totem solo air. my problem isnt bottoming out too much, its that the last inch of my rebound hardly ever is used. it doesn't have a floodgate so i believe its the DH one. sorry i dont completely understand this yet but could i just put on some slightly smaller shims?

    Um i think you placed this in the wrong thread, this is for the DHX rebuild, not the mission control tuning
  • 07-25-2010
    mtnbikinggolfer
    ugh lol fail
  • 09-02-2010
    jvaughn75
    FOX DHX 4.0 Shims
    I've read this post and it is absolutely fantastic! One question though; there is mention of the shim stack being in a different order for different years and bikes and such. How can I determine the year my shock was made?

    I rebuilt my shock this past spring, and during the ride after, the piston bolt came loose and the shims fell off. So I disassembled it again and reassembled it, but now I have no rebound. From what I've read so far here and other forums, the shims being in the wrong order can cause rebound issues. I bought my bike off ebay and I believe the frame is 2002 0r 2003, and I am only assuming that the shock is stock. Any help is greatly appreciated! :D