ADVrider

Go Back   ADVrider > Bikes > Thumpers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 12-20-2010, 07:06 AM   #1
rz35027 OP
Gnarly Adventurer
 
rz35027's Avatar
 
Joined: Dec 2007
Location: Vancouver BC
Oddometer: 212
LC4 shock rebuild parts?

I have blown the seal on my shock... oil on the bumper and it thunks pretty good coming up on full extension... 620 RXC

I would like to rebuild this myself and need to know what are the wear parts in an LC4 shock absorber... I know it's not the same as a PDS shock.

How much of this can be done without any special tools(?) besides the filling with nitrogen? The bleeding can be done... with care taken, by hand. Disassembly should be OK, reassembly should be OK, or, are there tools needed for the shaft seal?

I have a spare shock (with lots of hours) and an Adventure shock that I'd like to lengthen (take a spacer out) that will also need attention.

Can someone chime in with some advice pls?
rz35027 is offline   Reply With Quote
Old 12-20-2010, 08:14 AM   #2
airgord
What am I doing out here!
 
airgord's Avatar
 
Joined: Feb 2007
Location: Eloy, AZ.
Oddometer: 844
Is there anything on the LC4 thread? (bump)
airgord is offline   Reply With Quote
Old 12-20-2010, 08:38 AM   #3
col klink
the str8n'r
 
col klink's Avatar
 
Joined: Aug 2009
Location: North Ga.
Oddometer: 87
LC4 shock rebuild parts?

Quote:
Originally Posted by rz35027 View Post
I have blown the seal on my shock... oil on the bumper and it thunks pretty good coming up on full extension... 620 RXC

I would like to rebuild this myself and need to know what are the wear parts in an LC4 shock absorber... I know it's not the same as a PDS shock.

How much of this can be done without any special tools(?) besides the filling with nitrogen? The bleeding can be done... with care taken, by hand. Disassembly should be OK, reassembly should be OK, or, are there tools needed for the shaft seal?

I have a spare shock (with lots of hours) and an Adventure shock that I'd like to lengthen (take a spacer out) that will also need attention.

Can someone chime in with some advice pls?
RZ35027,
I have drawers full of special tools for all the different shocks and forks I do.
The lc4 shock is not that different compared to the pds shock other than only using one piston on the shaft rather than two.
I would think you'll probably need a shaft holder (14mm I believe) and a 14mm seal bullet tool to protect the new seal upon installing it.
I can't think of any thing else you have to have. obviously 150 or so psi nitrogen pressure.
While you are there you should consider a Racetech Goldvalve kit to make your shock that much better than oem.
PM me if you like.
good luck
__________________
1972 R75/5 (col. Klink) That junk's old, but it's str8

2008 KLR685 w/Stage1 porting, Stock exhaust and intake,
GMDATL Alignment Correction (str8n'd the frame)
GMDATL spec/Racetech Goldvalve Emulators,
GMDATL spec/Racetech Shock Goldvalve, remote reservoir, compression adjuster and a 400# spring.
It's str8 now but it wasn't when it was new.
parabellum tall shield

www.gmdatl.com
Kent Soignier
col klink is offline   Reply With Quote
Old 12-20-2010, 09:10 AM   #4
laramie LC4
crash test dummy!
 
laramie LC4's Avatar
 
Joined: Sep 2004
Location: Tucson, Az
Oddometer: 2,341
Quote:
Originally Posted by col klink View Post
While you are there you should consider a Racetech Goldvalve kit to make your shock that much better than oem.

yup, the gold valve is a HUGE improvement over the stock valving. well worth the money if you have the shock already apart.

laramie
__________________
DON'T TRUST CUT 7! HE IS A CROOK! ASK ME HOW I KNOW.

'12 LC8 990R, '02 LC4 640, '05 WR 450f (part-out), '98 XR400R, '76 KE100, '05 525 (Step-Child)
laramie LC4 is offline   Reply With Quote
Old 12-20-2010, 11:29 AM   #5
Luke
GPoET&P
 
Luke's Avatar
 
Joined: Aug 2004
Location: Idiotville, OR
Oddometer: 4,070
If you don't want to buy a shaft seal tool, just chamfer the shaft with some fine sandpaper and put the seal head parts on the shaft individually, then re-assemble the head on the shaft. There's no need for a shaft holder unless you're disassembling the clevis end, which shouldn't be necessary.

You will need something to hold the shock body and the reservoir body, and a really good pin wrench. The caps are on really tight. Installing a schraeder valve in the reservoir cap makes recharging the gas easier.

In addition to the shaft seal, you may need a reservoir piston seal, a shaft bushing and a piston bushing. The parts are the same on the older and newer shocks, so you can use the exploded diagrams on the newer mode parts fiche to see what you're getting into.

I'm happy with the stock valves, but did change the shims. For me, the stock valving from the '97 adv is way better than the newer ones with the shorter travel. The valving I settled on for my bike is pretty similar to the stock '97. The biggest differences are to account for extra weight and a heavier spring. I'd at least change the newer shock valving to match the older one. Obviously, your valving preference depends on how and where you ride.

Also, if you lengthen an Adventure shock, you'll need to use the taller spring collar from the 620 so that the spring doesn't hit the engine case at full extension. IIRC, to get the exact length of the longer shock you need to replace the 10mm spacer with a 2mm one. It's not just removing a spacer.
Luke is offline   Reply With Quote
Old 12-22-2010, 06:17 AM   #6
Tseta
Lost
 
Tseta's Avatar
 
Joined: Nov 2008
Location: Finland
Oddometer: 669
Quote:
Originally Posted by Luke View Post
...
In addition to the shaft seal, you may need a reservoir piston seal, a shaft bushing and a piston bushing. The parts are the same on the older and newer shocks, so you can use the exploded diagrams on the newer mode parts fiche to see what you're getting into.
...
Another good and informative thread about the LC4 shock.

I'm a bit confused about the different wearing parts, that might need replacement.

I tried to take a look at the fiche (click here), but I think there is a terminology disconnect here. KTM's names for these parts are confusing me.

I assume that the reservoir piston seals are numbers 87 and 88 on the diagram, parts 46811043 O-RING VITON 35X5 and 46810324 PISTON RING 3,9X1,5X138, correct?

For the shaft, the shock manual mention a dust seal. It must be number 24 on the fiche, part 46811044 DUST SEAL 1424, right?

The only other part that I see in the fiche that would be relevant is number 26, part 46811540S1 ADAPTER CPL. D=46, H=23 BA. What is this called, in layman's terms?

Where do all these parts stand in relation to what Luke listed? Which ones are the bushings, I couldn't find them on the fiche? Any other parts that I missed?

Cheers,

Tseta
Tseta is offline   Reply With Quote
Old 12-23-2010, 07:25 AM   #7
rz35027 OP
Gnarly Adventurer
 
rz35027's Avatar
 
Joined: Dec 2007
Location: Vancouver BC
Oddometer: 212
Good question on the translation of part numbers and laymans terms..
Can anybody help us out?
There is some good info in the LC4 thread... and some more developing here... thanks guys
rz35027 is offline   Reply With Quote
Old 12-23-2010, 02:55 PM   #8
Luke
GPoET&P
 
Luke's Avatar
 
Joined: Aug 2004
Location: Idiotville, OR
Oddometer: 4,070
Doh!, terminology.....

The shaft seal and the shaft bushing are not available separately from KTM. You can either buy a new part #26 for $105, or go to Mcmaster.com and buy them separately. They are part numbers 6679K18 and 90025K228. The bushing is soft and a bit tricky to get in and out so get a spare or two.

The piston bushing is #77, the reservoir seal is #87
Luke is offline   Reply With Quote
Old 12-23-2010, 03:14 PM   #9
rz35027 OP
Gnarly Adventurer
 
rz35027's Avatar
 
Joined: Dec 2007
Location: Vancouver BC
Oddometer: 212
Quote:
Originally Posted by Luke View Post
Doh!, terminology.....

The shaft seal and the shaft bushing are not available separately from KTM. You can either buy a new part #26 for $105, or go to Mcmaster.com and buy them separately. They are part numbers 6679K18 and 90025K228. The bushing is soft and a bit tricky to get in and out so get a spare or two.

The piston bushing is #77, the reservoir seal is #87
Thank you sir!
Are these parts equivalent quality (?)... from the prices that's a HUGE difference. $3.08 - bushing, $11.96 (100 pcs) seal... wow.
rz35027 is offline   Reply With Quote
Old 12-23-2010, 03:34 PM   #10
Luke
GPoET&P
 
Luke's Avatar
 
Joined: Aug 2004
Location: Idiotville, OR
Oddometer: 4,070
Quote:
Originally Posted by rz35027 View Post
Thank you sir!
Are these parts equivalent quality (?)... from the prices that's a HUGE difference. $3.08 - bushing, $11.96 (100 pcs) seal... wow.

The bushing looked the same- it's soft steel with a teflon coating. The seal looked like it was a tiny bit larger then the OEM- but the OEM was squashed, hardened and cracked so I can't be sure.

I put a couple of years and 15k miles on those parts; they never leaked and looked good when I did a rebuild.
Luke is offline   Reply With Quote
Old 12-23-2010, 03:50 PM   #11
rz35027 OP
Gnarly Adventurer
 
rz35027's Avatar
 
Joined: Dec 2007
Location: Vancouver BC
Oddometer: 212
I was bracing myself for a big hit with 3 shocks on the table... that's going to help alot!


Do you have recommended brand of fluid?
rz35027 is offline   Reply With Quote
Old 12-23-2010, 06:51 PM   #12
Luke
GPoET&P
 
Luke's Avatar
 
Joined: Aug 2004
Location: Idiotville, OR
Oddometer: 4,070
I like silkolene rsf pro 2.5wt. Brand is probably not so important. Weight is.
Luke is offline   Reply With Quote
Old 12-23-2010, 07:27 PM   #13
rz35027 OP
Gnarly Adventurer
 
rz35027's Avatar
 
Joined: Dec 2007
Location: Vancouver BC
Oddometer: 212
xlnt...
rz35027 is offline   Reply With Quote
Old 12-25-2010, 03:25 AM   #14
Tseta
Lost
 
Tseta's Avatar
 
Joined: Nov 2008
Location: Finland
Oddometer: 669
Thanks Luke for the explanations and the alternative part sources. I had a look on the McMaster site for the part numbers and did some research, to make it easier to obtain these parts, especially for those of us not in the US.

It seems that the shock shaft bushing is in fact just a "quite" standard 14mm plain bushing. This type of bushing could be obtained from, for example, INA ( click here). The bushing measures 14mm i.d., 16mm o.d. and 12mm in width. These bushings may be available with either steel or bronze backings, but as Luke said, the steel version should probably be used.

The shaft seal looks to be a quad-ring (an "o-ring" with an cross-section in the shape of an x). Converting the inch sizes to mm sizes results (at least close enough) in a 13,95mm X 2,62mm "standard size" quad ring. Buna-N material is equivalent with regular NBR.

-------

I have some further questions as well. The WP shock manual is slightly vague at best. I hope someone can shed some light onto these issues.

Is it necessary to calibrate the new bushing with the calibrating mandrel when replacing it? Interestingly, KTM supplies these shaft seal parts as "one piece", but the service, according to the manual, still requires fidgeting with the individual components.

How about the reservoir piston, then? Is it necessary to unscrew the reservoir body from the shock casting (using the special tool) to gain access to the reservoir piston? Why couldn't one just unscrew the reservoir cap and take the piston out from that side? This way, one could leave the reservoir body in place and so many special tools wouldn't be needed to service the shock.

Cheers,

Tseta
Tseta is offline   Reply With Quote
Old 12-25-2010, 04:36 AM   #15
dentvet
Beastly Adventurer
 
Joined: Aug 2008
Location: hunt country virginia
Oddometer: 1,221
suspension toolage ?s

who sells a good adjustable pin wrench?

i have a nitrogen cylinder and regulator, what else do i need for recharging operations?

i have a vacuum pump collecting dust, what's it good for?
dentvet is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 09:13 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014