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Lay off the Levers
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Discussion Starter · #1 · (Edited)
(Xpost from the Turner Forum)

I had some time to kill while waiting for some parts to install my new fork so I decided to pop it open to see what's inside and to install a travel indicator instead of the ghetto style zip-tie.

Before this, the most recent model Zoke I've wrenched on is my '06 66SL which this RC3 will be replacing.
Things are fairly different so I had to get some help to figure out how to open it.

It was somewhat complex in comparison to the '06 but only as a first time experience. Having done it now, it's not too tough at all. Check out the exploded diagram provided by jncarpenter in the link above for additional info. It does not tell the whole story but it's helpful. Anyway this is good to know if you want to change your wipers or seals or send your lowers out to get painted.

Disclaimer: I not an expert of any kind. I did not get any info directly from Marzocchi. I would assume they'd prefer you don't d!ck around beyond changing the oil and even then I'm sure they'd rather you have a pro do it. If you knacker your fork, sac-up and buy the replacement parts.
Warranties aren't for hamfisted wrenches.

Hokay, let's assume you already know what the fork looks like. If not, put the tools down!



*If you know where this is going and just need to know how to get the foot nuts off, skip down to that section.*

Note: that most of the bolts and wrenching surfaces are made of light, SOFT aluminium. Tool marks are tough to avoid but rounding and stripping is easy, so make sure your tools are square, well seated and held firmly.

If you just want to drain/change the oil, or if you want to change the spring, you only need to remove the top cap(s). If you want to pull the lowers off or remove the RC3 Cartridge then it gets into some tricky bits.

Removing the top caps is easy.
For the right side:
Loosen and remove the small hex bolt on the large red preload knob.


*Note: It's a good idea to have the fork over a towel or cloth because there is a tiny detent ball hopefully sitting in one of the dentent recesses. Be careful not to loose it!


Under the knob is a tiny detent spring it is only held in place by grease. Be careful not to loose it either.


Hold the fork securely and loosen the top cap using either a 26mm socket or a large adjustable. Remember the metal is soft.

If you use a adjustable wrench (AKA nut rounder), make sure it's good and square and fitted tightly.
The flats are not very tall so it's a good idea to file off the recessed bevel from the socket.


Filing a socket down only takes about 10 mins. It's worth it.


The liberated right top cap:



What lies beneath:
Plastic spring cap. There's one on the bottom of the spring also.

*Note, the spring cap has different diameter inserts on each side. The spring side has a thicker ~20mm dia insert
The side that faces away from the spring is thinner an is only ~18mm dia.

This is the thicker side of the spring cap:


The coil that does all the toil:


There's a plastic spring cap below the coil. It might be held on by grease but it will probably drop off in the leg.

Notice how it's flipped over and askew. Can't put the spring in with it sitting like that.

You can retrieve the lower spring cap by pouring it out with the oil:


Standard spring stats:
~250g(.55lbs) OD:30mm ID:20.5mm


What's left inside the right leg is the telescoping base rod that it attached to the lower foot nut and clipped to the inside of the stanchion:

This rod is what the spring and spring cap sit on and compress against.
It moves and turns freely so you cannot simply unscrew the foot nut to remove the lowers. I'll get to that later.

Left Leg top removal
Remove the air valve cover and the rebound knob:


The top cap can be opened using a standard cog set lock ring tool:
(sans center punch)


I found it very tightly torqued so be sure hold the fork securely and get good square leverage.

Once open you can compress the fork some, extend the damper rod and pour out the oil. You can see the top of the RC3 cartridge here:

The rod is attached to the lowers by the foot nut.

BTW at full compression the fork has about 3mm btwn the dust wiper and the crown:


FOOT NUTS!

You need a small impact wrench. Get the smallest torque one you can find, hopefully adjustable. Home Depot has a Husky for about $50 bucks.
I believe the Butterfly type is best but they were out when I went.
The good news is I just returned a bunch of unused stuff I had lying around and got a store credit that paid for the whole thing. :thumbsup: Go check under your workbench folks!

Removing the lowers:
Right Foot nut
As mentioned before, the Right lower leg is attached by a foot nut. The base rod it is threaded onto turns freely so you cannot simply unthread it.

Use a 15mm socket and a small impact wrench:


The wrench will vibrate and turn the nut faster than the rod can keep up with. The nut will spin free:


Left foot nut:
Loosen the TWO set screws on the small red compression knob:



There is just enough hex flat on the shaft to hold the damper rod with some pliers. You can turn the foot nut with a 17mm wrench:

Be careful not to damage the rod end. Also I believe you can do the job using the small impact driver.

Remember the flats on the footnut are only 3mm tall. If you use a socket, remove the inner bevel first or you'll probably round the nut:


After you remove the foot nuts, slide out the RC3 damper rod. The lowers can now slide right off:

Note the telescoping base or fixing rod in the right stanchion. (left viewed from the front)

The base/fixing rod is attached to the inside of the right stanchion with a c-clip:

I saw no reason to remove it, but if you wanted to, this is the binder.

With the stanchions off I took the opportunity to install a rubber o-ring on each leg to use as travel indicators.

I had extras so I put one on each leg to use as a max and recent travel marker:

I used some faucet O-rings from Home Depot. They were just thin enough to fit in the 3mm gap at full compression. But since they're rubber even a little contact with the dust wipers is NBD Especially considering most ppl just use a zip tie.

Reassembly:
Put some slick honey on the ends of the stanchions and around the inside of the seals and dust wipers, and you might want to rub some fork oil halfway up the stanchions as well, just to help get things off to a smooth start.

On the right stanchion, pull the right leg fixing/base rod out some.
Then carefully angle and slide the stanchions back in past the dust wiper lip. Work carefully to align the stanchions as they go past the inner seals and upper and lower bushings. Keep an eye out for the fixing rod and help it through the bottom hole of the right lower. Pull the threaded end through the hole and start threading the foot nut on the rod.
You might consider using long thin needle nose pliers or tweezers to GENTLY hold the threaded rod until you've got the foot nut halfway on. Then use the 15mm socket and impact wrench to (Set to 1 or 1.5) and tighten it up.
NASCAR fans: The impact makes short work of this, so don't go crazy, it's a foot nut not a lug nut. use short bursts.

Next insert the RC3 rod into the left leg and start the foot left foot nut on the threaded end. You can use the same method you used to remove it, or use the impact wrench again. (with the 17mm socket)
You might want to use the impact to snug it down if you can't get a solid grip with pliers or are concerned with damaging the shaft.

While the fork is still about half compressed, extend the RC3 rod cap and pour the oil into the left leg. 220ml is what came out of mine that's what I put back in.

Pump the RC3 rod a dozen or so times to prime it. You'll feel the bubbles cavitate inside the rod. Keep pumping it till it's smooth. You can also pump the whole stanchion to move the oil about a bit.

Put some slick honey around the thick side of bottom spring cap and stick it onto the spring. Slide the spring into the right leg making sure the spring cap does not fall off and possibly flip over.

Note this is what it looks like if it is falls off:


Extend the fork and pour the oil back into the right leg ~260ml came out of mine so that is what I put back in:


Put the upper spring cap on, with the thicker side facing the spring:

Then replace the right top cap.

Putting the compression knob back on can be tricky the first time.
Put a dab of grease in one of the detents and stick the ball there:


The spring in the adjuster knob is also held in place with grease.
Note that the point between two flats points directly at the spring:

Align the point of the black compression shaft so it points at the detent ball. Then align the top cap so the spring is over the ball.
Peek underneath as you lower it down and you should get it right away.

Tighten the lock screw. Replace the rebound knob and air cap on the left side and you're done. :thumbsup:


It sounds more complicated than it is and the 2nd time around won't take long at all.(if you ever have to do it)
Getting a impact seems like a lot but you can always use it later to tighten those loose spokes. :D

Measurements:
Lower weight: 1020g w/axle 870g w/o
Upper weight: 1240g w/base rod
Oil: 260ml left 220ml right.
Compression knob 23 clicks
Right foot nut 15mm
Left foot nut: 17mm x 3mm tall
Right top cap: 26mm
Std spring: 12-3/8" long, 30mm OD ~20.5mm ID
Spring Caps 20.2 OD & ~18mm OD
Good luck and if you break anything forget you read about it here!
Thanks to the folks in the Turner forum for the tips that got me started.
Also thanks to Blackagness for the tip on which impact wrench to get in the Marzocchi support thread.
 

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Lay off the Levers
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10,127 Posts
Discussion Starter · #4 ·
I took the cheap route.
Nashbar lockring tool.
Husky sockets and wrenches.
Some park stuff (none used here)

Snap-on make kickarse tools. My brother used to be an auto mech. IIRC back in the day you could only buy em off the truck!
 

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16,457 Posts
Bikezilla said:
I took the cheap route.
Nashbar lockring tool.
Husky sockets and wrenches.
Some park stuff (none used here)

Snap-on make kickarse tools. My brother used to be an auto mech. IIRC back in the day you could only buy em off the truck!
The nashbar tool looks great. I never use a wrench, and the knurling would be pretty nice.

Snap On is nice. I do Armstrong. Just as good, and if you know where to get it from, a steal. Have both, and dig them.
 

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I dig trails!
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5,611 Posts
wormvine said:
The right leg has the forks only spring and mechanical preload.
The left leg has the RC3 damper and nothing else?
The left leg will also have oil level BO tuning. So during BO both legs will have spring force.

Great write up Bikezilla! :thumbsup: :thumbsup: :thumbsup:

Thanks! I had missed this when it was originally posted.

P
 

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Mr.P said:
The left leg will also have oil level BO tuning. So during BO both legs will have spring force.

Great write up Bikezilla! :thumbsup: :thumbsup: :thumbsup:

Thanks! I had missed this when it was originally posted.

P
Word!
After comparing the 66RC3 design to the RC2X design, I really like the RC3 mechanisms.
The spring can be replaced very easily on the RC3. From the pics, it looks like you just pull the top cap off and the spring comes out. On the RC2X, you have to remove the top cap from the cartridge shaft. Plus there is a spring on both legs as well on the RC2X.

Oil changes also look to be a whole lot easier as well. No need to fight the springs sticking up out of the leg to get oil height right and adding/adjusting oil looks to be a snap.

If Marz gets their issues fixed I just might look at a 09 RC3.
 

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Awesome guide this :thumbsup:.

I bought a 2010 66 RC3 and am in the middle of fitting enduro fork seals as well as attempting to fix a weap on the bottom of the left foot nut/compression damping adjuster.

Weird thing is when I opened her up, I pulled out the spring, which I expected to be be yellow but was grey/black colour (suggesting medium strength spring anyone?). Also noted that the spring was still in plastic wrapping!!!!! :confused: Is this normal?

Anyways I have a 2008 RCV that the RC3 replaced. So gonna take the spring out of that as the RC3 felt bit too soft for me, so hopefully see some difference there.

Have attached image of spring if anyone is interested. Doesn't seem right that its got a plastic wrapper on it.

BBB
 

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