If it's currently not working no harm in at least pulling it apart. Once it's in peices you can check to see if there's any substantial wear on the stanchions. If they look ok clean then you can rebuild it or maybe just clean, grease and top of with oil. If that works, great. If not rebuild kits are cheap.

Should be a fun project, or at least a learning experience.

 

Pull it apart. There’s no harm in taking something that doesn’t work now apart. New seals and oil maybe all it needs and that’s cheap.

 

I had an old Sid that felt like garbage. Finally got around to taking it apart. Cleaned up all the dry sticky grease from the legs stanchions & seals. Slathered on some Slickoleum grease & it's like new again. I did have to replace the seals & metal seal retainers on the lower leg bolts, but I literally have dozens from my Pike.

 

well I pulled it apart tonight and don't feel any scratches on the stanchions. There are a couple spots were it appears the anodizing flecked off but they feel pretty smooth, and I can see some evidence of slight wear of the anodizing in other spots but all very smooth. Will have a closer look in the morning. It definitely needs wiper seals, I could tell that before I took it apart.

 

Enduro make wiper seals for them. Same as Psylo. Different OD to current RS 30mm seals.

 

I pulled the air-side rod out all the way and saw some very faint scoring at the upper end and felt a bit of a pinch as I pulled. I can't feel it with my finger but I can feel it with my fingernail, barely. So I thought maybe I'd better inspect the upper arm to be safe. (feel free to discourage me) I got to 7:12 in this video

where he pulls it out but mine ain't like that. I don't want to assume anything since I've never done this before, but I assume I need to remove the circlip at the bottom end and pull the guts out that way on mine?

 

Yah, I think this one is better for mine, except for the lockout which I don't have

But I don't want to rebuild if i don't have to. I will try and get a pic of the scoring and see if you experts think its necessary. Feel free to discourage me at any time.

 

Yah, I think this one is better for mine, except for the lockout which I don't have

Yaaahh....at 15:30 he twiddles them washer-thingies but doesn't replace them. They are wavy washers that are supposed to look bent and broken. But one of my flat washers is also bent, so I'll replace them all anyway. I found the service manual which should help me and the other 3 living people who are still riding Duke XC's .

https://d9i5ve8f04qxt.cloudfront.ne...udfront.net/RWC/1832/resources/oe-fork-manuals/pdfs/rs/02rsdukeserviceguide.pdf

 

Well thanks for not talking me out of it, now I'm in it and can't back out. Good thing too.

This is what i found on the right side.

Those washer thingies don't look so good, do they?

I was pretty sure the other side was fine, so its good I didn't trust my intuition.

No, thats not good. An o-ring should not look like 2 c-rings. And

On this side there were only 2 washer thingies, and one was "broken" like the other side. Should there have been a third? Also the rebuild kit shows something that looks like the "broken" washer, so maybe they are supposed to look like that?

https://www.amazon.com/gp/product/B001CJXBR2/ref=ox_sc_act_title_1?smid=AMY4I718ZUBOU&psc=1

I'll need to look at them in the morning but most of the other o-rings looked pretty good. But I suppose I'll have to buy a full rebuild kit anyway. I'll get some motorcycle fork oil, and maybe ask my bike shop for a blob of grease. Anything else I need, other than wiper seals and foam rings?

 

Well thanks for not talking me out of it, now I'm in it and can't back out. Good thing too.

This is what i found on the right side.

View attachment 1318259

Those washer thingies don't look so good, do they?

I was pretty sure the other side was fine, so its good I didn't trust my intuition.

View attachment 1318261

No, thats not good. An o-ring should not look like 2 c-rings. And

View attachment 1318263

On this side there were only 2 washer thingies, and one was "broken" like the other side. Should there have been a third? Also the rebuild kit shows something that looks like the "broken" washer, so maybe they are supposed to look like that?

https://www.amazon.com/gp/product/B001CJXBR2/ref=ox_sc_act_title_1?smid=AMY4I718ZUBOU&psc=1

I'll need to look at them in the morning but most of the other o-rings looked pretty good. But I suppose I'll have to buy a full rebuild kit anyway. I'll get some motorcycle fork oil, and maybe ask my bike shop for a blob of grease. Anything else I need, other than wiper seals and foam rings?

Welp...based on my understanding of the exploded diagrams in the service guide I linked above, there should not even be a wavy washer on the damper side. As you can see in the upper pic there is a wavy washer and 2 flat washers, one of which is so bent that it looks like a wavy washer. And it shouldn't have been there anyway. I'm just going to put 1 flat washer on that side.

On the spring side there should be 1 wavy washer only. I sure hope I'm right.

How could this have been so effed up?

 

Kind of off topic, but I remember I had a compressor that wasn’t working right. My buddy called me a ***** for not wanting to take it apart. Long story short, it was a $12 gasket lol.

Glad you tore into it.

 

OK, I'm gonna need some experienced help here so I have someone to blame when I screw this up. My rebuild kit and seals came, so I'm ready to do this. But I don't even know if I have the 80 or 100mm version, and I don't know how to tell. The washer arrangement appear to be the only difference between the two based on the schematics on page 10 and 11 of the service manual, but my current washer arrangement doesn't quite agree with either of those two. I'm also not quite sure what they mean at part #14 in both diagrams, where they say *includes snap rings for 80 and 100 mm configurations.

I only see one snap ring so I'm not sure what point they are making.

 

https://d9i5ve8f04qxt.cloudfront.net › ...PDF
2002-2004 duke air ser vice guide - cloudfront.net

The above manual says there is an innersnap ring in the damper side stanchion that needs to be removed if you have an 80mm. (Pic 15) if you have a 100mm that small ring won't be present.

That's all I know.
If that link doesn't work Google 02_04dukeairserviceguide

 

it appears that I have the 100mm then. There was no 2nd clip

 

Please don't mention the RS Duke around me.

I had a 2002 Stumpjumper FSR with a Duke on the front of it. That fork tried to kill me by flinging the front of the bike in every different direction whenever I'd hit a bump. That fork had murderous intent.

I might buy it from you just so that I could take a sledge hammer to it. And then burn it.

 

I was browsing the *uke posts on the forum and learned of your sorrowful grievances against the *uke. If it doesn't work better than that once my servicing is complete, I just might sell it to you!

 

Weeeeeeeeeeeeellllll...that appears to have been a big fat waste of time and money. The fork might work as well as it did before (and I'm not sure how well it worked then) but I see no improvement. It still won't hold more than 110-120 psi after I get on it. It still makes a clunking sound.

Rather disappointed the kit didn't have several o-rings that it should have had. No o-ring for the schrader valve, although I inspected it and the one on there looked good. I replaced the valve stem, just in case it was leaking. There was no o-ring in the kit for the hollow bolt on the bottom of the damper side, so I had to reuse that one too. Same for an o-ring that slides on the damper piston rod.

I guess I know where my stimulus check will be going.

 

any recommendations for a decent replacement fork for $200ish?

Still not sure I've given up on this one completely. Seems like an air leak shouldn't be that hard to fix, so maybe I'll come back to it.

 

any recommendations for a decent replacement fork for $200ish?

Still not sure I've given up on this one completely. Seems like an air leak shouldn't be that hard to fix, so maybe I'll come back to it.

That sucks man. But at least you had something to do during all this down time lol.

I have an Suntour Epixon. It's okay at best. It works and all, but it takes constant maintenance to keep it happy. At least if you do anything heavier than green and blue XC trails.

I'm sure you did, but did you grease the threads of seals of the air chamber? Or is it just the O ring that's causing the leak? You can always take the old ones into a hardware store and see if you can find the same size.

 

The best fork for 200ish is a brand new manitou markhor. You can upgrade the damper later if you want and have really an excellent fork.

The cheapest new fork option are suntours off ebay. They're as little as $125 right now. They're quality forks that are well made, but they are low end. Either way, they're better than a duke was on a dukes best day.

 

The best fork for 200ish is a brand new manitou markhor. You can upgrade the damper later if you want and have really an excellent fork.

The cheapest new fork option are suntours off ebay. They're as little as $125 right now. They're quality forks that are well made, but they are low end. Either way, they're better than a duke was on a dukes best day.

I will look into those, thanks. Maybe i'll use my stimulus on a Markhor, which sounds way more badass than a Duke.

 

Marzocchi makes some nice forks that last forever. (Depending on model) where are you located?

 

LOL! I replaced my Duke with a Marzocchi and it was a night and day difference. Sooo nice.

Here's my RS to Marz' history:

1997 RS Indy > Marz' Z2
2002 RS Duke > Marz' MX
2015 RS Pike > Marz' 350 NCR

Every time it's been a monumental improvement in performance.

 

In New Mexico at the moment. Aren't M's expensive? I'm on a budget, just trying to restore an old Stumper to functional moderate XC use. I see the Rockshox Recon is a bit more expensive than the markhor, but its also heavier. It does take v-brakes though.

 

You can find decent deals on older Marzocchi Z2' & Z1's occasionally. Under $100 is a pretty good deal. I've purchased a handful to rebuild over the years. If they are really nice they are worth $175. Plus side to those is they are easily rebuildable, seals & oil only. They will typically last decades, simple & effective. Also they hold their value pretty well. The Z1's below are pretty decent. Not mine, look nice.

https://www.ebay.com/itm/Marzocchi-...-Moto-Design-Coil-Oil-100mm/283839609546?hash=item421628baca:g:FMAAAOSw9D1ei8Z8

Any idea what year your stumpy is? Depending on the year stock fork travel may have been less than what that Duke offered. May allow use of a smaller fork.

 

Keep in mind those old marzocchis are only as good as the maintenance that has been done on them.
The ones that never got an oil change ended up with wear debris building up on the bushings and chewing out the stanchions. At which point they're scrap metal.

 

Very true, but I've had around 15 marzocchi Z's I've rebuilt all but one were great. And even the ugly one wasn't nearly as bad as the worste rockshox or fox forks.

So yes marzocchi's can go bad but I'd guess they will outlast any similar vintage fork with similar service history many times over.

 

I ended up buying a new Recon Silver just because I wasn't keen on doing another rebuild and finding out it was no good, and it is possibly the only air shock still made for my 03 Stumpy . But maybe now I can keep an eye out for a sweet deal on a used Marz, if you think that would be a significant upgrade

 

OldBlue950 has generously blessed me with this fork. For the sake of anyone else who works on one of these, I'll post my observations.

I went through it using a guide for 2002 Duke air forks, and it looks like it had been assembled correctly. But when I put it back together, I noticed a lot of clunking from the fork. I believe this is coming from the "seal head" on the damper (it's not really a seal because this damper is open bath).

The 2002 Duke uses a Hydracoil damper, but the 2003-2004 is Hydracoil 2. I believe this fork is a 2003 or 2004 Duke XC.

I managed to find a parts list for the 2003-2004 Duke, and here are some pics from that parts list.

 

The HC2 fork has more "stuff" in there keeping the damper seal head in place -- a wavy washer sandwiched between two flat washers. I think the 2002 HC doesn't have one of those flat washers, for whatever reason.

 

yeah it clunked before and it clunked after. I hope you have better luck than I. You said it held air in pm, but it always went down to about 100 lbs after riding on it, for me.

 

I haven't ridden on it yet, so that may end up being a problem. It held 180 psi overnight, though.

The inside of the left leg looks really smooth to me, so I think that the air piston should seal OK. I gave everything a liberal dose of slickoleum on installation, so maybe that helps.

It's nice to have something to work on; we're getting soaked with rain here.