Disassembling shocks

J

jrd-28

Member
I've got a pair of shocks which came off my '28. They're pretty well rusted together, what a surprise.

To disassemble, it looks like I need to clamp the base in a vice, grab the outer cover with a pipe wrench, and unscrew it. Is there any particular trick there? Is it ok to heat them up? I haven't been able to budge the first one I tried with a 2 foot long wrench.

I guess the corrolary question is if they're so badly rusted that I can't get them open without heat, does that mean they're junk?

Thanks for any wisdom.
 
I wouldn't mess up the cover by using a pipe wrench. Several years ago I made 3 sets of special tools to work on shocks. I sold one set on ebay, sold one set to Jim Sinclair in Wisconsin, and kept one set for myself. If you do a search for "tools for working on shocks" you might get lucky and find some pictures. The all steel strap wrench I made to remove the covers won't leave marks.

BTW, Jim used his tools to work on his shocks, and the last I knew he has his set of tools for sale.
 
Ok, thanks for the hints about tools, I'll look around for those.

I can easily make my own strap wrench too, so maybe will just go that route.

On the basic technique, it sounds like I'm looking in the right direction. What about the question of heat?
 
You might find it easier to remove the covers if you loosen the lock ring below the cover first. Once you back it off a ways, it will be easier to get penetrating oil down into the threads of the cover.
 
I am not a shock man by any measure, but I found that the man in our club that rebuilds shocks had to go through 10 shocks to find one set for me that he could rebuild. Your one set from your car may not be enough for you to rebuild. Jack
 
Here is how to take apart shocks.

Do NOT put in a BBQ grill.

First you need to heat the area between the seal ring and the cover. You are trying to burn out the seal. It makes life easy. You are not trying to heat things red.

I have a tight fitting ring with a pin and can move the sealing ring, but the following will make life easier. Pay attention some science ahead.

Metal expands when beat on and shrinks when heated past the plastic point. We are taking advantage of this to get these covers off without super fancy tools (I made the fancy tool, but not super fancy so it is a bit easier for me).

So I take a small ball peen hammer and holding the shock in my hand I go around doing lots of light taps. My goal is to expand the threaded area of the cover. At some point you can clamp in a big vice (it is better if you have a really big heavy vice- but that is another story) and use a strap to get the cover free. If it does not move then you have not hit is enough. It take a lot of hits light hits. The covers will be surprisingly easy to move if you do it right, but you are still likely to need a strap wrench to get it started. The strap wrench is more about how the cover is gripped then how much force you can put on it.

So now you have the cover and the ring off.

Now what?

I bought a deep impact socket and borrowed a 1/2" impact from a friend that works on trucks. I clamped the shock body in my over 100lb vice (let me tell you a large heavy vice is are really good tool to have in your shop). This is important as anytime you are about to use impact force to break something free you have to be sure you have the item held with enough inertia that the impacts are not being lost to moving the fixture. If you have to bolt the shock to something large and heavy do that. Then put the impact and let it rip. It takes a bit of beating to get it going. Several shock bodies need need a couple of heat and cooling shock treatments to break the inner cover. There I heated the body up, not red, and dropped it in water a couple of times and then the impact got the cover off.

Last is the needle valve. This is delicate. You have to heat up the vane body to burn out the packing and break the rust free. You can not put much force on the head of the valve without breaking it.

As a general rule. If you look in and see rust through the fill hole then the shock is not good. You are taking it apart for the cover and the needle valve.

Now when it comes time to put the cover back on you need some heat. Fit the cover and see how loose it is after cleaning the threads. Then do a couple of red spots around the threaded area. Important, let it cool down some then put in water. Then try it and see how tight it is. You need a snug fit. It is important to understand that you MUST let the temp of the cover get down to that of the cover before you decide to shrink it more. You can over shrink if you do not allow for the cover to cool enough.

Be careful about parts. There are different variations and parts do not mix well.

I have only taken apart about 20 shocks so others might have better ways. This work well for me and involves using my copies of tools I think Tom Weisburg (sp) made and ideas from Tom Moniz.
 
Heat them up first but not to the point of red hot. Then douse them in cold water. Do the same process again. What you are doing is expanding and shrinking the components. The parts will be eaiser to remove rather than not.

Pluck
 
I found that it is better to bore holes in a good size post and mount the shock there when using a big tool on it as the vice might get damaged depending on how much force is put on it. Down force can be used when mounted on a post which helps. A lot of them aren't very pretty when you finally get them open but a few are fine.
 
I`m with Pluck. by tapping around the cover you are expanding the cover and you WILL have a hard time getting them to seal. I have been there and done that.
also do NOT use a pipe wrench on the on the covers it makes a mess of the cover.
you never know if there are re buildable until you get them apart.
 
Why not in a BBQ may I ask, we don't toss it into the coals just heat it up to 500 or 600 degrees and let it cool. Then the next time your grilling do it again .

Does anyone have pictures of the tools ? I would love to see the correct tools:D






Kevin in NJ said:
Here is how to take apart shocks.

Do NOT put in a BBQ grill.

First you need to heat the area between the seal ring and the cover. You are trying to burn out the seal. It makes life easy. You are not trying to heat things red.

I have a tight fitting ring with a pin and can move the sealing ring, but the following will make life easier. Pay attention some science ahead.

Metal expands when beat on and shrinks when heated past the plastic point. We are taking advantage of this to get these covers off without super fancy tools (I made the fancy tool, but not super fancy so it is a bit easier for me).

So I take a small ball peen hammer and holding the shock in my hand I go around doing lots of light taps. My goal is to expand the threaded area of the cover. At some point you can clamp in a big vice (it is better if you have a really big heavy vice- but that is another story) and use a strap to get the cover free. If it does not move then you have not hit is enough. It take a lot of hits light hits. The covers will be surprisingly easy to move if you do it right, but you are still likely to need a strap wrench to get it started. The strap wrench is more about how the cover is gripped then how much force you can put on it.

So now you have the cover and the ring off.

Now what?

I bought a deep impact socket and borrowed a 1/2" impact from a friend that works on trucks. I clamped the shock body in my over 100lb vice (let me tell you a large heavy vice is are really good tool to have in your shop). This is important as anytime you are about to use impact force to break something free you have to be sure you have the item held with enough inertia that the impacts are not being lost to moving the fixture. If you have to bolt the shock to something large and heavy do that. Then put the impact and let it rip. It takes a bit of beating to get it going. Several shock bodies need need a couple of heat and cooling shock treatments to break the inner cover. There I heated the body up, not red, and dropped it in water a couple of times and then the impact got the cover off.

Last is the needle valve. This is delicate. You have to heat up the vane body to burn out the packing and break the rust free. You can not put much force on the head of the valve without breaking it.

As a general rule. If you look in and see rust through the fill hole then the shock is not good. You are taking it apart for the cover and the needle valve.

Now when it comes time to put the cover back on you need some heat. Fit the cover and see how loose it is after cleaning the threads. Then do a couple of red spots around the threaded area. Important, let it cool down some then put in water. Then try it and see how tight it is. You need a snug fit. It is important to understand that you MUST let the temp of the cover get down to that of the cover before you decide to shrink it more. You can over shrink if you do not allow for the cover to cool enough.

Be careful about parts. There are different variations and parts do not mix well.

I have only taken apart about 20 shocks so others might have better ways. This work well for me and involves using my copies of tools I think Tom Weisburg (sp) made and ideas from Tom Moniz.
Click to expand...
 
Tom beautiful set of tool and thanks for sharing the info and pictures. As a tool maker I made more of a spanner wrench to work on mine. I like you design better and if it's cool is it ok to make a set off your design. Thanks
 
A strap wrench or chain wrench is better for the cover. Also, I used to put some oil in them and heat them up in a bucket of hot charcoal. Sure can make a stink so do it away from the neighbors if possible. Quince with water right after heating. I have heated around the cover with torch in stubborn cases.Agreed, don't use pipe wrench.
If there is ANY shaft wobble or off-center.....don't waste your time. Also, if you pull the filler plug and full of dirt or rust....probably wasting time also.
 
Last edited:
jw hash said:
I`m with Pluck. by tapping around the cover you are expanding the cover and you WILL have a hard time getting them to seal. I have been there and done that.
also do NOT use a pipe wrench on the on the covers it makes a mess of the cover.
you never know if there are re buildable until you get them apart.
Click to expand...

Quite frankly, you are going to have a hard time getting them to seal no matter what you do.
 
I quit building for others a long time ago because only 1 in 10 had a fighting chance 10 years ago. Now, it could be 1 in 50!

On the covers, I always used Permatex and let them sit overnight before filling. Leaking was a problem with shocks on the showroom floors in 28-31!!!
 
vulture said:
Tom beautiful set of tool and thanks for sharing the info and pictures. As a tool maker I made more of a spanner wrench to work on mine. I like you design better and if it's cool is it ok to make a set off your design. Thanks
Click to expand...

Thanks, and be sure to make enough sets to sell. :)
 
I thought I read in the restorer that you had to tap two pins into the shock body before trying to turn the outer cap. I skimmed the thread but didnt see a mention of this critical first step.

Did I miss that? Or am I thinking of a different part/process?

*edit*
I just went back and re read it. The pins are part of a different part of the process. They are inside.

Sorry for the confusion.
 
Last edited:
TRP said:
I thought I read in the restorer that you had to tap two pins into the shock body before trying to turn the outer cap. I skimmed the thread but didnt see a mention of this critical first step.

Did I miss that? Or am I thinking of a different part/process?

*edit*
I just went back and re read it. The pins are part of a different part of the process. They are inside.

Sorry for the confusion.
Click to expand...

No you do not need to do that. I have seen that too and I do not know why that person does that.
 
the two pins (per say) are not pins but air vents at the top of the chamber that let the air out of the chamber when oil come in from the bottom. the have a little grove in them.
 
Those pins must be taken out and cleaned. Then after install I verify that they let air out by shooting some cleaner through them.
 
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