Disassembling Compression Damper

gharmon
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gharmon
Edited Date/Time 11/26/2013 11:49am
I'm tying to disassemble the compression damper on a Showa twin chamber fork. I'm replacing the free piston seal, at least that's the goal. I have searched here, youtube, thumper talk, etc for a write-up/video on how do get this thing apart to no avail.

I have already taken the nut on the end (opposite end of fork cap) and all those little washers off. From pictures I've seen it appears that the shaft that's left should unscrew from the rest of the unit. I have tried to loosed this shaft buy turning it with pliers. I didn't want to apply too much pressure and screw something up. Is this area thread locked on as well?

Am I going about disassembling this thing from the wrong end? Does it come apart from the cap end instead? I can see another nut inside the coil spring, does this have anything to do with taking it apart.? Any help will be greatly appreciated as this bike has been down far too long for what was supposed to me fork seals only dammit!! lol
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slipdog
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slipdog 11/25/2013 10:27am
11/25/2013 10:27am
You can do it either way, but yes, there is usually a lot of thread lock on them. I like to remove the compression valve tower from the shaft instead of the shaft from the cap. I clamp my 32mm socket in a vice to put the cap in and use a large non toothed pair of channel locks to get enough leverage to break it loose.
gharmon
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gharmon 11/25/2013 12:58pm
11/25/2013 12:58pm
slipdog wrote:
[img]https://p.vitalmx.com/photos/forums/2013/11/25/37238/s1200_image.jpg[/img]
Slipdog, thanks for the tip. After doing it this way I got it to break loose but instead of it coming lose where I wanted it too (the far end of the damper) it broke loose up near the cap end inside the spring. So basically I still cant get the piston off. There is really no where to grip it now cause it would crush the tube in the middle. Any ideas? lol
gharmon
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gharmon 11/25/2013 1:18pm
11/25/2013 1:18pm
Here is what I'm left with now:

The Shop

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slipdog
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slipdog 11/25/2013 1:58pm
11/25/2013 1:58pm
I had that happen in the past, clean the thread locker off and remove the lock nut. When you put the free piston back on cover the threads with a heavy coat of assembly grease and be careful not to damage the new seal when reinstalling. Clean the threads of all grease, and put the lock nut back on about a thread higher than where it came off from.

Make sure the clicker is turned all the way counter clockwise, add thread locker and screw the shaft all the way back down until it bottoms out. In theory the nut should be only about one thread above the female end of the cap and use an open end wrench to tighten the lock nut to the cap. You may have to grind down your wrench to fit between the coils of the pressure spring.

To remove the old seal you will have to strip the piston of the bushings and o-ring and heat up the piston good because the seal will not come out if you don't. somehow they seem to weld themselves in and won't budge without heat. Good luck!
gharmon
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gharmon 11/26/2013 6:55am
11/26/2013 6:55am
Hey slipdog I appreciate your input a lot. Thanks man!! Should I heat it with a torch or like in an oven. I've read of people doing both.

Again, thanks a lot,

Gerald
slipdog
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slipdog 11/26/2013 9:29am
11/26/2013 9:29am Edited Date/Time 11/26/2013 9:30am
I use a torch and heat it from underneath where the seal is for just a few seconds and that's enough to allow it to pop out. I use a flat blade screwdriver to grab one edge of the seal and pry up using the shaft of the screwdriver on the opposite side as leverage.
Cajun Kamikaze 11/26/2013 11:07am
11/26/2013 11:07am Edited Date/Time 11/26/2013 11:08am
Brian, saw you like to use those toothless channels. Check these out. I got a pair and they are one of the most versatile pair of pliers I've used. Because of their cantilever hinge and even application of toque along the length of the grip, I've even used them as a press to replace my linkage bearings and the like.

http://www.amazon.com/Knipex-8603250-10-Inch-Pliers-Wrench/dp/B000X4OG9…

"•Parallel Jaws allows Infinitely Variable Gripping of all widths making it Excellent for Gripping, Holding, Pressing and Bending"
slipdog
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slipdog 11/26/2013 11:49am
11/26/2013 11:49am
Those are pretty cool Jeff, never seen those before. The one I use for this application has a concave grip which helps grab the round tower. It requires some kind of horizontal pin spanner that I've never even seen so I have to improvise. I got it from my dad and he got it from grandpa, lol. A lot of my speciality tools are custom made from normal tools and a grinder, I usually refer to them as my "KTM tools". Whistling

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