400ex shock rebuild kit?
- Thread starter lowkhalbalr
- Start date
Showa manufacturers them.
There is a post by phragle including pictures on how to rebuild them. I used it (and a few silly questions through PM's) to rebuild my shock and it worked GREAT!
I lobbied unsuccessfully to have it stickied lest it get burried under a million silly question posts and lost forever. Here's the link:
http://www.blasterforum.com/do-yourself-20/how-service-rebuildable-shocks-10664/
There is a post by phragle including pictures on how to rebuild them. I used it (and a few silly questions through PM's) to rebuild my shock and it worked GREAT!
I lobbied unsuccessfully to have it stickied lest it get burried under a million silly question posts and lost forever. Here's the link:
http://www.blasterforum.com/do-yourself-20/how-service-rebuildable-shocks-10664/
Blaner
Your Friendly South African Ambassador
They would also charge killer money....
Unless you need it revalved (most people don't) or resprung (most people don't) I would simply pull it apart myself, clean everything up, replace the seals as necessary, refill it with ATF (as phragle suggests) and then take it somewhere to have the nitrogen recharged.
I rebuilt my 400ex shock last year and it's been working great since. I used ATF (synthetic even!) in mine and it's been working great too.
Unless you need it revalved (most people don't) or resprung (most people don't) I would simply pull it apart myself, clean everything up, replace the seals as necessary, refill it with ATF (as phragle suggests) and then take it somewhere to have the nitrogen recharged.
I rebuilt my 400ex shock last year and it's been working great since. I used ATF (synthetic even!) in mine and it's been working great too.
Blaner
Your Friendly South African Ambassador
is the nitrogen really necessary? most people do not know that our normal air we breathe is actually 78% nitrogen, 21% oxygen and small fractions of argon and so on making up the rest. Sure nitrogen is inert, but do you really think adding a a little more nitrogen is actually going to make a difference? it has the same compressibility and stability under compression as oxygen. Its the same farce as the Nitrogen in tires, its just a marketing goose laying golden eggs if you ask me. the only reason people experience better tire life from adding nitrogen is because they have to pay for it hence they take more care to make sure the pressures are right. unless you have a source of ignition in your shock to cause oxygen to ignite, i do not believe in the whole nitrogen story
Phragle swore by it. I took it up and got 150PSI nitrogen for free because a buddy works at a tire filling station, otherwise I would have put air in it...
It's true that air is mostly nitrogen, but oxygen changes volume much more as it heats up. Nitrogen is much more stable as it's temperature increases.
Most people will never use that particular feature of the shock. Mine has never been above the ambient temperature, I simply don't use it hard enough to have a heat problem. Phragle, however, desert raced his quad. Extremely high ambient temperatures coupled with extreme heavy duty use = overheating issues.
If you're using the shock on an MX track (lots of shock travel) or in a desert racing situation (lots of shock travel coupled with extreme heat) then I would say you absolutely have to get nitrogen.
If you're using it to try and soften your ride while you trail ride, air will probably work OK for that use. I'm not too sure about how air will react if the bladder bag ever develops a leak.... but if you use air, the only thing you have in a rebuild is some transmission fluid, you can afford to rebuild the shock once a year and check and see the condition of the bladder.
It's true that air is mostly nitrogen, but oxygen changes volume much more as it heats up. Nitrogen is much more stable as it's temperature increases.
Most people will never use that particular feature of the shock. Mine has never been above the ambient temperature, I simply don't use it hard enough to have a heat problem. Phragle, however, desert raced his quad. Extremely high ambient temperatures coupled with extreme heavy duty use = overheating issues.
If you're using the shock on an MX track (lots of shock travel) or in a desert racing situation (lots of shock travel coupled with extreme heat) then I would say you absolutely have to get nitrogen.
If you're using it to try and soften your ride while you trail ride, air will probably work OK for that use. I'm not too sure about how air will react if the bladder bag ever develops a leak.... but if you use air, the only thing you have in a rebuild is some transmission fluid, you can afford to rebuild the shock once a year and check and see the condition of the bladder.
its 40 bucks a shock to have them rebuilt.... im sorry but rebuilding your shocks yourself is just plain a stupid idea... the odds of you effing something up are hugeee
awesome. thanks guys
oh and btw nitrogen is more stable and less susceptible to changes in temp, thats why it is used in tires; plus it weighs less. however blaners statement is true filling a shock with compressed air over nitrogen wouldnt make much of a difference.
oh and btw nitrogen is more stable and less susceptible to changes in temp, thats why it is used in tires; plus it weighs less. however blaners statement is true filling a shock with compressed air over nitrogen wouldnt make much of a difference.I'm sorry, but I've already done it and it cost me $4 in ATF. There really isn't a whole lot to taking a 400ex shock apart; 2 snap rings, a dust cover to pop off, and (if you need to replace the seal) one nut holding the shim pack and seal on. The only thing you need to be careful about is the shim pack if you remove it, not to get the order of things wrong.
Using Phragle's step by step (pictures even) instructions the process is simple and straight forward.
Maybe for someone who does not have any technical competence, the $40 is reasonable but there is a difference between rebuilding and tuning a shock absorber... There are companies out there which offer rebuild services (which is what I'm talking about and for $40 you probably are too) which is too expensive IMHO because of the simplicity of the design of the showa (honda 400ex rear shock) shock.
If you need to have a shock tuned, that's a different ball game all together. If you are doing MX tracks or desert racing, the shocks have to be tuned PERFECT and the service should be purchased by companies who have tuned thousands of shocks custom taylored to a specific weight and ride type. If you're a hardcore racer, you should pay for that service, it's worth the money.
Using Phragle's step by step (pictures even) instructions the process is simple and straight forward.
Maybe for someone who does not have any technical competence, the $40 is reasonable but there is a difference between rebuilding and tuning a shock absorber... There are companies out there which offer rebuild services (which is what I'm talking about and for $40 you probably are too) which is too expensive IMHO because of the simplicity of the design of the showa (honda 400ex rear shock) shock.
If you need to have a shock tuned, that's a different ball game all together. If you are doing MX tracks or desert racing, the shocks have to be tuned PERFECT and the service should be purchased by companies who have tuned thousands of shocks custom taylored to a specific weight and ride type. If you're a hardcore racer, you should pay for that service, it's worth the money.
