# Fox DHX 5 Home rebuild



## Nick_M2R (Oct 18, 2008)

Hi all
I recently noticed that my 09 dhx 5 coil has a oil leak on the main shaft, so i think the main seal is blown, which is probably my fault as i used to turn the shaft round when i took the spring off :bluefrown: 
Well after many unanswered calls and emails to the Aussie rebuild center (dirt works)
I have decided to do a rebuild my self, i have looked through many sites and have a really good idea of how to do the rebuild.
One question remains however and that is were can i get a new o ring seal?
Could i just go to a auto store or hardware store and buy a identical one? or could i buy one from mojo in the uk?
Would love to hear peoples thoughts
Cheers


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## davep (Mar 11, 2005)

Seal suppler in any city should be able to match it for you.

I _think _the specs were posted @ Ridemonkey most likely by Udi...either way it should be easy to match.

edit here is his post:

_Hey guys - quick reply since i'm late for work

The shaft seal is only an o-ring, there is another yellow thing that looks like an oil seal but it only ACTS as a dust wiper - so you can reuse it. The o-ring is black and sits in its own seat behind the yellow wiper.

The o-ring is an imperial size:

12.29 x 3.53 (N70)

Where 12.29mm is the ID, 3.53mm is the cross section width and N70 is the hardness.

Replace that and you should be set. If it's not leaking or seeping at all then there's no need_


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## AznRider (Jun 20, 2008)

Please post some pics of the strip down...i'm subscribing to this one!


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## 4JawChuck (Dec 1, 2008)

davep said:


> Seal suppler in any city should be able to match it for you.
> 
> _The o-ring is an imperial size:_
> 
> ...


Uhh...that works out to a 31/64" ID and 49/64" OD ? Not exactly either.

That is no standard size Imperial o-ring, nor a standard size metric one either. Need to know if its Nitrile, Buna-N, or Silicone too. Kinda important to know what type of o-ring it is to even order one, my guess is its Nitrile but who knows? They don't make o-rings in various durometers without special order either. Unless you know for sure what weight oil to use and can get the proper o-ring I wouldn't touch that job with a 10 ft pole.

Send it in, be cheaper in the long run...thats a critical component and no place to be experimenting unless you can test it safely on a dyno somewhere.


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## Nick_M2R (Oct 18, 2008)

4jawchuck: 
I would love to send it in to get fixed, but after 15 unanswered emails and 10 phone calls that end up saying "this number has been disconnected", to the local fox service center, ive given up on them, besides life's and adventure and i want to learn how to rebuild things like this myself, will save me a **** load of time and money in the future, and i love to tear things apart for the hell of it.

AznRider:
ill will certainly post pic's up of the rebuild process, i've i wanted to see one for a long time, it would be a great addition to this site. Im surprised that no one else has posted one yet seeing how popular the dhx's are. Just gotta get the fluid and seal as well as some tools and in the summer holidays ill be tearing her down .


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## Jerk_Chicken (Oct 13, 2005)

Been meaning to change the oil in mine since I went to a CCDB.

Most important thing is to get the IFP depth right. I wouldn't be surprised if one can get a more supple shock by increasing depth slightly.

Now for filling, one can use hose couplings, but the res could get in the way. A tall cereal container from Rubbermaid or similar, but only big enough for the shock could work as the bath. Make sure the shock is clean so you can use that oil for oil changes.


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## Gruntled (Jul 7, 2008)

G'day Nick,
Try posting it up on Farkin.net too. Udi is a suspension wiz and frequents that forum, parts and stuff would get some good responses. I'd love to know how you do it, I have a DHX 5 I need serviced!


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## Nick_M2R (Oct 18, 2008)

Gruntled said:


> G'day Nick,
> Try posting it up on Farkin.net too. Udi is a suspension wiz and frequents that forum, parts and stuff would get some good responses. I'd love to know how you do it, I have a DHX 5 I need serviced!


No prob Gruntled
Thanks for the heads up, ill post it up ASAP and shout for Udi, see wat i can dig up

Cheers mate


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## AznRider (Jun 20, 2008)

One of my friend took apart his 5th elephant on his uzzi slx and took the seals to the local seal specialist store. The auntie asked him if he wanted something better and he duly paid 3 bux for the new o ring(lol?) He swears it runs better now but too bad he didnt documented it


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## Nick_M2R (Oct 18, 2008)

AznRider said:


> One of my friend took apart his 5th elephant on his uzzi slx and took the seals to the local seal specialist store. The auntie asked him if he wanted something better and he duly paid 3 bux for the new o ring(lol?) He swears it runs better now but too bad he didnt documented it


Sweet!
Ill be taking the seal to a local seal store and see what they say, im gonna buy a couple and ill definatly post up the specs of the seal.

Cheers Azn


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## 4JawChuck (Dec 1, 2008)

I hear ya Nick, its a PITA.

The size listed previously is a standard Imperial size o-ring, spent some time and looked it up.

Here is the specs and part number;

Part# : *AS568B-206*, 1/2" ID (nominal) - 3/4" OD (nominal) - 1/8" Cross Section (nominal).

Its listed here;

http://www.oringswest.com/

Here's a good primer on o-ring material compatibility.

http://www.allsealsinc.com/pdf/National%20O-Ring%20Catalogue-2.pdf

Most places carry Nitrile and Buna-N on the shelf, Viton might be superior but would be a special order in most cases.

Good luck!:thumbsup:


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## Nick_M2R (Oct 18, 2008)

Thanks a million for the specs 4Jawchuck!
Ill prob shout up a aussie o ring manufacturer cause the one you provided is american, and geez! $75 for one o ring?!? at today's exchange rate that wont convert to well....
Anyway thanks for the specs though!


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## 4JawChuck (Dec 1, 2008)

No worries mate, you will find one locally. That 1/2"X1/8"X3/4" o-ring is very common.

The part number is a universal o-ring order number and is an ASTME standard #. However that website has some outrageous prices! I'll bet you will find one locally for less than a $1 USD each. 

I think the reason why they list such outrageous prices online is to prevent the guy who wants just one or two from ordering through them.


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## Nick_M2R (Oct 18, 2008)

4Jawchuck:
Just found this website this morning

http://www.norseal.com.au/ior.htm

They also seem to have the o ring ill need:

O-RING IMP N70 BS206 1/2 x 3/4 x 1/8

im bout to give them a ring and see how mcuh they cost and if i can buy them in bulk.

Also while were on the topic, what oil can i use?
Would fork oil work and if it does what weight?


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## 4JawChuck (Dec 1, 2008)

Hmmm just so you know I am no shock expert although I have done many motorcycles over the years.

I would start at a 5 wt oil first, if thats too light I would try a 7 wt next. For the best seal compatibility I would use a good quality synthetic oil like Amsoil, Spectro or Finish Line. Honestly any oil will work but getting an accurate wt is pretty important and will seriously affect how the shock behaves with various damping settings. Different brands of fork/shock oils have different flow characteristics even if their weight is the same stated on the bottle.

You do know you are in uncharted territory here doing this yourself, FOX does not have any recommendations other than saying *"DON'T DO IT".*

I think the biggest problem you will face is how much oil to put in after its apart, might be wise to measure exactly how much comes out when you disassemble. A milli-litre here or there won't be the end of the world but you are experimenting with a very important safety related suspension component and *I don't recommend you do it yourself*. Assembly order will also be important and where you put the oil is critical.

Why not call Fox and ask to talk with an engineer or mechanic there, you might run into a kind sort who can give you some specs and save you some trouble.

In this day and age, me recommending anything other than sending it back to the factory or authorized repair facility for overhaul opens me up to liability and I say *don't do it yourself!*

Thats my story dude and I'm sticking to it.

Think about the consequences of screwin it up, you could be killed or seriously disabled if that thing packs it in off a 4 ft roller at 50 mph. If I was you I would pack it in a box and send it off to Push and have them look after you, it will come back better than new and be more reliable, those guys have already done all the experimenting and their knowledge and experience is worth the money they charge. They will dyno it for you and give you back a component better made than when you first got it out of the box.

I know it sucks to be without while its gone off for overhaul but in the long run you will be better off and have a new component you can trust. I think everyone will agree that doing this yourself is fraught with danger at every step if you mess it up and you only have one chance to get it right when your life is on the line.

I had a Fox Float air shock stick down on me and I nearly lost in on a short downhill on my XC bike, the idea of it happening on my DH bike at 50mph on a steep rock garden makes me cringe...I can taste the gravel.

Think about it.:skep:


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## AznRider (Jun 20, 2008)

I was about to ask if we could use 15wt fox fork oil...


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## William42 (Oct 29, 2006)

4JawChuck said:


> *"DON'T DO IT".*


Lot of people rebuild DHX's. Lots of people reshim them themselves. Its not uncommon. Fox doesn't give out "how tos" because they don't want to deal with idiots breaking things and trying to get warranty, and because they don't want to be held responsible if something goes wrong.

That doesn't mean its incredibly difficult to do. I'd talk with socket and udi over on ridemonkey/farkin.


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## 4JawChuck (Dec 1, 2008)

William42 said:


> Lot of people rebuild DHX's. Lots of people reshim them themselves. Its not uncommon. Fox doesn't give out "how tos" because they don't want to deal with idiots breaking things and trying to get warranty, and because they don't want to be held responsible if something goes wrong.
> 
> That doesn't mean its incredibly difficult to do. I'd talk with socket and udi over on ridemonkey/farkin.


Ha-ha this kills me, when you get your engineering degree and stamp you can put your approval on this backyard rebuild and give some advice on how to do it. Instead you refer him to someone else to take responsibility?

Pleeeease.

No one said its rocket science, if it was this would be the "rocket downhill" forum...which is exactly what he could be doing if it goes bad.

Too funny.

Lets look at the economics, $3000+ bike, $0.05 cent o-ring.

$105 rebuild from Push.

I'm betting on the $105 dollar insurance policy, my front teeth are worth more than that!

$105 bucks is cheap, get another paper route if this is too much buy in for riding mtn bikes regularly. There isn't even a waiting period right now if you check the site below!

Push DHX Rebuild Services


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## William42 (Oct 29, 2006)

4JawChuck said:


> Ha-ha this kills me, when you get your engineering degree and stamp you can put your approval on this backyard rebuild and give some advice on how to do it. Instead you refer him to someone else to take responsibility?


Not trying to make it personal, and I'm not an engineer, you're right.

But I do like doing things myself, and will do so when I get the opportunity. If I feel like I'm going to be in over my head with something, I'll call the company and get help, or send it wherever its necessary (push or fox in this case). Am I qualified to tell people how to do it? Nope, but I still feel confidant I could find enough information about it to decide for myself whether or not I felt confidant doing it myself, as I'm sure the OP can decide for himself too.

Doing it with it with detailed pictures, descriptions, and people you can ask questions of is better then doing it blind (in most cases!), which is why the internet and information sharing is great. I'm not telling the OP to pull it apart and cross his fingers, I'm telling him where he can find detailed information on whats involved and ask questions, so as to help him decide if he's confidant he can do it himself.

For what its worth, as long as he's not a gorilla, worst case scenario he pulls it apart and can't get it back together again and has to send it back. Any problems he induces if he rebuilds it will be pretty evident the second he jumps on it. Rebuilding shocks is NOT rocket science.


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## jamesdc (Oct 31, 2005)

Stock fox oil is 10wt. Make sure to back off all the adjustments before you take it apart and measure the depth of the ifp when you open the resivor so you know what to set it back to.


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## davep (Mar 11, 2005)

Nick_M2R said:


> 4Jawchuck:
> Just found this website this morning
> 
> http://www.norseal.com.au/ior.htm
> ...


So after a day of arguing, turned out the info I posted was correct...hmmmmm

Anyway, you do not want to use fork oil (at least inexpensive stuff) for several reasons. Generally fork oil is non-synthetic or semi synthetic where as 'shock' oils are fully synthetic, THe different chemical formuals are designed to give differing properties. Shocks see higher pressures, more wear, less service, and much higher temperatures than any fork would. Therefore you will find shock oils typically having a much higher viscosity index (temp/viscosity stability) as well as longer life with less decomposition/breakdown. Of course for some high end oils like redline and silkolene, they are fully synth and designed for the harsher environment of a shock to begin with.

Fox uses Torco fluids, and the RSF medium (racing shock fluid) in particular. You can find more info about bike mfg re-labled oils here: http://www.peterverdonedesigns.com/bikesuspension.htm

and a bunch about oils, how they differ, and what the number mean here: http://www.peterverdonedesigns.com/lowspeed.htm

BTW, N70 = N Buna (or nitrile rubber).....in a durometer of 70 (one of two standard durometer, the other bieng 90) nitrile and Buna are the same thing....ie your standard black rubber o-ring.


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## Sov (Nov 4, 2005)

Just so you know, Dirtworks aren't distributing Fox suspension anymore - Netti are doing it these days.

Re. oil, go to a motorbike shop and grab half a litre of Motul/Silkolene etc rear shock fluid (not fork oil) in 7w/10w whatever. Grab some Slick Honey or similar from a bike shop.

O-rings as has been said are standard half inch o-rings. You can buy o-ring kits from your local hardware store that have a whole range of sizes including the one you want, or you could source some from somewhere like CBC Bearings (they have stores all over AU and can supply DU bushes too if yours are rooted)

Rebuilding is reasonably straightforward if you take your time and do your research properly. Read up on ridemonkey and farkin as there are lots of threads that cover the procedure. But in a nutshell:

1. Release air from resi
2. Make sure that you have released air from resi!
3. Undo resi cap and measure the internal floating piston (IFP) height
4. Undo the main seal head whilst fully extended and remove shaft/piston
5. Either undo the piston bolt or the top eyelet to allow you to slide off the seal head. If you undo the piston bolt, apply some loctite before assembly.
6. Pop the old o-ring out of the seal head and replace it. Give the dust seal a clean in situ then smear some grease on the seals/bush.
7. Undo the bleed screw in the IFP and tip out the oil.
8. Submerge the whole lot in oil then rebuild it whilst submerged, cycling the piston in and out to purge any air. Do up the seal head.
9. Set your IFP height whilst extended, put the bleed screw in, resi cap etc then regas.

There are other methods that you can use that don't require you to rebuild submerged, like my pic in this thread:
http://forums.farkin.net/showthread.php?t=150415

But as I said, just have a look through some threads before getting stuck into it and you should be fine.

PS. WIth shock building, cleanliness is the key! Contaminants are bad - don't get any dirt or grit in your oil.


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## Nick_M2R (Oct 18, 2008)

4JawChuck:
I fully understand and respect the point you are making. In no way shape or form would i hold you responsible if the advice you gave me was involved in my shock failing. The truth is, i am mechanically minded, and love to take things apart and see how they work, i also like to now how to do my own maintenance. If i run into trouble, i would send it off to the rebuild center


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## 4JawChuck (Dec 1, 2008)

Sorry if I turned this into a pissin match, not my intention. 

I am an engineer and also a machinist and industrial mechanic and I know shock rebuilding is not rocket science, I've rebuilt enough sled shocks over the years to have made fixtures to hold them in the right position for rebuilding. I like doing it myself too!

However, Fox is not a stupid company...they freely distribute information on how to rebuild their forks. Why not their shocks? Probably because the average home handy man does not have the proper equipment to rebuild them properly. You can only imagine the stuff they see come in the front door on a regular basis in a bag of loose parts. 

We know the rough diameter of the o-ring but the exact material...are we sure this is the right size? Not with 100% assurance..right? The right oil will make a huge difference also. The company I work for specifically makes components with custom o-ring sizes so that if "Joe on the street" tries to fix it it might work for awhile but it will fail soon after. 

Thats the world of big business for ya! Engineers are bastages. 

I did a search for a "how-to" on rebuilding these shocks and could find nothing, there has to be a reason for that...not like its a new product. The internet is a great place for information sharing but its also a great place to get BS.

I know if I was having difficulty finding a local rebuilder, I would pull it and buy a new one...sell the leaker on e-bay or craigslist. Might explain why there are always so many for sale.

Good luck Nick, appreciate you won't sue me if it goes bad...but I have a feeling your lawyer won't be so kind.:thumbsup: 

P.S. can I get that in writing with a signature.


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## Nick_M2R (Oct 18, 2008)

Well so far so good.
Just got the shock disassembled, IFP depth measured (8.5 by 2.5 shock)
Got my Castrol shock fluid
and tommorow im taking the seal to a oring supplier to get it measured for a new one
Also got a crap load of detailed pics of the process, so the tutorial is going good.
Heres a pic of the DHX in all its glory:


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## Sov (Nov 4, 2005)

Nice work! Take the time to bleed it properly and you'll be sweet.


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## bxxer rider (Jun 7, 2008)

what??? i thought shocks where more complicated inside? remember getting all the air in the oil chamber is VERY important, one reason why i blow my shock twice, mojo rebuilt it but didnt get all the air out so some of the stroke had no dampening so it over compressed and blow a seal...twice
so good luck 

(might want to point out my shock is a vanilla so there not quite the same)


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## William42 (Oct 29, 2006)

needz moar shimz


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## Jerk_Chicken (Oct 13, 2005)

bxxer rider said:


> what??? i thought shocks where more complicated inside? remember getting all the air in the oil chamber is VERY important, one reason why i blow my shock twice, mojo rebuilt it but didnt get all the air out so some of the stroke had no dampening so it over compressed and blow a seal...twice
> so good luck
> 
> (might want to point out my shock is a vanilla so there not quite the same)


Nope, not too hard to manage. You're paying for marketing, development, shortfalls, etc. In the end, you're looking at designs that either push oil or a piston that pushes through the oil. The development is how to valve it. Other than that, it's fairly simple, really.

The prices you see are due to the mystery and perceived complications inside.


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## Nick_M2R (Oct 18, 2008)

William42:
There are actually quite a few shim's on the piston, however in the picture, they are just stuck to the piston, so it dosen't look like there are many there but they are there


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## davep (Mar 11, 2005)

The pro-pedal valving is still hidden inside as well. This not only provides pseudo low speed compressin damping, but also a pressure and thus position sensitive damping nature to the DHX. IT is what allows the varying size and pressure in the resevior to ramp up damping to prevent bottom out.


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## Nick_M2R (Oct 18, 2008)

Well, got the o-rings this morning
And just rebuilt her......
And it Worked!!!!!
been out riding her for a couple of hours really giving the shock a work out, and no more leaks! The shock rides freaking awesome!!
Now im just finishong my tutorial on how to fix the dhx
Stay Tuned!!!


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## William42 (Oct 29, 2006)

Nick_M2R said:


> William42:
> There are actually quite a few shim's on the piston, however in the picture, they are just stuck to the piston, so it dosen't look like there are many there but they are there


Oh I was only joking, cross forum reference to an inside joke, but cool writeup, stoked it worked out well for you


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## Gruntled (Jul 7, 2008)

Nick_M2R said:


> Well, got the o-rings this morning
> And just rebuilt her......
> And it Worked!!!!!
> been out riding her for a couple of hours really giving the shock a work out, and no more leaks! The shock rides freaking awesome!!
> ...


You bloody ripper! That's excellent. Mine really needs some lovin.


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## bxxer rider (Jun 7, 2008)

Jerk_Chicken said:


> Nope, not too hard to manage. You're paying for marketing, development, shortfalls, etc. In the end, you're looking at designs that either push oil or a piston that pushes through the oil. The development is how to valve it. Other than that, it's fairly simple, really.
> 
> The prices you see are due to the mystery and perceived complications inside.


lol okay fair enough


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## bxxer rider (Jun 7, 2008)

any chance a fox vanilla rc shock would re-build in pretty much the same why? (not exactly of course)


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## Nick_M2R (Oct 18, 2008)

Tutorials done!


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