What's inside those shocks?

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What's inside those shocks?

Ever wondered what is inside the shocks on your Bronco/Stallion? Or did you find that out when a shock “broke” and you couldn't repair it? Here is a step-by-step guide on how to disassemble and reassemble one.

First a word of caution. Each shock contains two springs that are under compression. Use caution when working on them to prevent injury from these springs. Secondly, there are four plastic/nylon sleeves inside each shock. Each is very fragile, and if one is not already broken, there is a chance a breakage will occur if they are mishandled. Remember, these things are already about 50 years old, and like people, they break easier than they used to.

I apologize if the pics don't quite line up with the narrative. Read thru all this before attempting this project. You'll have a better idea of what to be aware of.

Do one shock at a time. After removing one of the shocks, lay it down on a clean work surface that you are not afraid of getting dirty. View the shock from the standpoint of how it's mounting surfaces line up. The flats of the shock's upper and lower tubes should be facing the same way.

Mark a reference line on the lower cover about 1+” below the lower edge of the upper cover. I placed some masking tape on the pictured shock so the mark would show up better.

Now place another mark on the lower cover, about 90 degrees around from your beginning point. This will be used as a reference point when reassembling the shock.

The grease in these shocks dried out decades ago and will need loosening up. Spray some light lubricant up inside the upper cover. This will help reduce friction when taking it apart. You'll see why once it is apart. Lightly compress and release the shocks several times with your hands to work this lube onto the moving parts. Once the shock moves up and down freely, go on to the next step.

Now you are ready to take the shock apart. For illustration and photography purposes, I clamped the upper end into a vise so I had a free hand to use with the camera. You may wish to do the same. Or you can just grasp the shock with both hands.

Compress the shock together so that the upper cover goes down to the original reference mark you made on the lower cover, about 1+”.

KEEPING the covers compressed, slowly twist the upper or lower cover about 90 degrees around to
the second reference mark.

Once at that mark, SLOWLY release the tension on the shock while AT THE SAME TIME
continually giving a slight twist to the covers, as if you are unscrewing a lid from a jar. Don't twist too much. If you lubed it right, and are slightly twisting as you slowly relieve your compression tension,
you will see the two halves extending apart. You will notice the nylon sleeves mentioned in the second paragraph.

Continue to relieve tension until the two halves come apart. Keep an eye on the four nylon sleeves so you don't lose them.

Here is a pic of a disassembled shock with the sleeves still attached.

It consists of an upper cover, two upper-cover nylon sleeves, a “heavy” gauge spring, two more nylon lower-cover sleeves, a “light” gauge spring, and the lower cover.

Sometimes the springs will take a bit of coaxing to come out. You may need to pick them out with some wire or pliers. Make a note regarding these springs. Each has an “eye” that is slightly “bent”. This bend corresponds to the bend in the mounting flanges on the covers. You'll need to remember this upon reassembly.

Now for those four nylon sleeves. If you were lucky, yours remained in one piece. They are fragile, and if they should break, you are pretty much up the creek. I don't have a solution regarding suitable replacements for damaged sleeves. Maybe a forum reader has a solution they can offer. The four sleeves are pictured below.

As you look at them, you can see these sleeves serve several functions. One, they hold the upper and lower sections together against the tension of the springs. Secondly, they function as lubricated guides to keep the upper and lower covers from rubbing against each other, reducing stiction. Plus, they also keep the shock halves “aligned”, meaning they keep the two halves from flexing or folding in half.  

Notice there are two styles of these sleeves. One style has a raised dimple on it's outer curved surface. This sleeve fits inside the upper covers.

The other two sleeves have their dimples on the inside curved surface. These sleeves fit outside the lower covers.

Also notice that their sides are not square but are at angles, as in a parallelogram. These angles are the reason you “screwed” or twisted the upper and lower covers apart as you relieved tension.

Now is the time to gently clean everything. A degreaser will work fine on the covers and springs. But use a mild cleaner on the sleeves. Anything harsh may weaken them and may result in cracks or their total destruction. Hopefully the lubricant you sprayed into the shocks before dis assembly loosened most crud from these parts, making it easier to give them a final cleaning. Now is also a good time to repaint the upper covers, and maybe send out those lower covers to be re-chromed!

To re assemble the shocks, most everything is done is the reverse order of dis assembly. First, apply some sort of greasy lube to the springs. This will help prevent corrosion and keep them from squeaking as they compress and flex against their covers. I used silicone grease. Insert the springs into their respective covers, making sure their eyelets are aligned with their respective mating flange. A fully inserted spring will not be sticking out much, if any.

Now the tricky and delicate part. The nylon sleeves need to be lubricated, but not with anything that may dissolve them. Once again I used silicone grease. Coat them thoroughly, inside and out.

Place the sleeves with the dimples on their inner curves onto the outside of the lower covers. The dimples should fit inside the small holes in the cover. The grease will help hold them in place during assembly.  

Now place the other greased sleeves, the ones with their dimples on the outside of their curve into the inside of the upper covers. The dimples should again fit inside the two small holes in the upper cover, with grease holding them in place. You may need to remove the spring first, insert the sleeves since there will be more room to work, and then replace the heavy spring inside the upper cover.

Now it is time to rejoin the upper and lower halves. This is done in reverse order of dis assembly. Be careful that you do not damage the sleeves. They will have a tendency to detatch from their covers. Use patience, or have someone nearby to help guide things as you compress the two halves together.

Working from the 90 degree reference point used during dis assembly, align the two halves and slowly insert the lower half into the upper half, while keeping an eye on the sleeves. As you compress the halves together, slowly twist them as if you were screwing them together with right-hand threads. (Remember those angled sides on the sleeves? These help you “thread” it about 90 degrees as you compress at the same time.)

Once you can “feel” that the sleeves have “meshed”, and that you have twisted and compressed the two halves together to the first reference point you marked on the lower cover, look to be sure the shock mounting tabs are in alignment with each other. Note: my original reference marks are not shown in the pics, although I placed some masking tape on the lower cover as a reference.

Now you may begin to slowly relieve the tension of the shock. Use caution that it doesn't come apart and send projectiles in every direction, similar to a rocket shedding it's stages.

If you were successful, you will have a freshly lubricated shock, and you will be unharmed.

The silicone grease may leave some residue on the lower cover as the shock moves through it's range of motion. Wipe excess grease off with a rag, and this step may require frequent repeats until excess lube had been removed. Plus grease may work it's way out through the small dimples in the upper cover. Simply wipe it off until none reappears. But remember the grease on those sleeves is what lubricates them, helping the shock move without stiction or squeaking.

Does anyone know if the dimples protruding thru the upper cover should be painted or left natural?

In a worst case scenario, a shock with broken sleeves will not stay together. One could fabricate some “struts” to replace the shocks. It will result in a rigid frame, but the bike will still be rideable. Or replace the shocks with a pair from a small motorbike. I did that on one Stallion, and although it rides much stiffer, it still looks fairly original.

I welcome any comments and/or suggestions. There may be a better way of doing this. So speak up!

Repeat with the other shock, and go ride that bike!
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Re: What's inside those shocks?

Great tech article! Thanks so much for posting. This will surely help so many other Vrroom! enthusiasts.