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!!!!!!!!!!!!!!!!!!!!!!!!!!!!
( I know the hosting sites arnt liked by many people, but sorry it will have to do for now :D )
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
Thanks for the guide Nick, It really helped me figuring out what was wrong with my shock !
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
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.
Originally Posted by croft92
Don't ride it, open the shock back up and check it out.
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...
its not the piston bolt :( i am very sad ..dont know what to do ....help me guys with some ideas
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.
Ok sorry guys for leaving this thread dead for awhile, have been mega busy starting my new life at college and Uni
Originally Posted by croft92
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 :???:
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!
Originally Posted by FreeRideABullit
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:
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!
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!
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:
Originally Posted by AaronJG
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:
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
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.
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?
Originally Posted by Nick_M2R
Thanks for creating a very useful guide! :thumbsup:
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)
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:
I meant: though I as a complete newbie....
Originally Posted by cesalec
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
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.
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...
Does anybody know the o-rings sizes on a DHX 5.0 and the stock shim stack?
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!!!!)
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.