One of the most intimidating tasks in fixing up a truck has to be working on shocks. Shock absorbers seem to take on a stigma of being an intricate part only to be worked on by a trained professional. Well I am here to tell you that they are in fact nothing to be feared and can be easily worked on in your very own garage!
Begin by removing the three Allen screws that hold the wiper seal in
To show how easily shock work can be done we are going to walk you through a simple revalve on a set of 2.5" RaceRunner by Sway-a-Way race shocks. For this we took a trip over to Sway-a-Way's shop in Chatsworth California and meet up with Engineer Brian Bell.
The list of tools you need to disassemble your RaceRunner shock is very minimal and there are no specialty tools. All you need are a 5/32" Allen Wrench, small flathead screwdriver, pair of pliers, a 7/8" wrench (closed or open, your choice), a bench vise, and some clean rags (shop rags, not dish rags as I'm sure your wife wouldn't like that too much).
The seal block is the first thing to come out of the body
Start by placing the shock upside down in your vise and secure it by clamping onto the cylinder cap. It is a good idea to place a rag between the cap and the vise so that you don't scratch or otherwise mare the caps surface. You are going to want to make sure that the shocks shaft is fully extended since this will make removing it much simpler. At this point you need to remove the nitrogen from the reservoir to depressurize the shock. Do this by simply pressing the Schrader valve just like letting air out of your trucks tire.
Here you can see the entire shaft assembly being removed from the shock body
You are now ready to start taking the shock apart. Start by removing the three Allen screws in the wiper seal cap. After you slide the wiper seal cap up the shaft and out of the way the seal carrier will be visible. Press this piece down just enough to see the circlip and remove it using your small flathead screwdriver (or a small pick if you happen to have one). With the circlip removed the entire shaft assembly will be ready to come out. Remove the shaft slowly and steadily to avoid spilling the oil inside. We can now start the revalving!
To begin revalving you will need to remove the shock body from your vise making sure again not to spill any of the oil inside. Place the shock against a wall or in a corner where it won't be disturbed while you work on the valving. Place the shaft assembly into the vise and secure it using the rod end. You can also secure it via the shaft by using a hogged out block of soft wood or soft metal such as aluminum. Never clamp the shaft in the vise by its self as this will cause scratches and/or gouges in the shaft which will lead to premature seal and shock failure. Next remove the 7/8" locknut that is located at the end of the shaft, with this off you can now remove the piston and valving shims. Be careful not to lose any of the valving shims when you remove the piston from the shaft and make note of which way the piston came off. Remember, Compression is on the bottom and Rebound is on the top. Once you have installed your new valving shims place the piston back onto the shaft and tighten the locknut. The shaft is now ready to go back into the body.
Using a 7/8" wrench remove the lock nut | 
Carefully remove the piston and shims from the shaft | 
This is the bottom side of the piston, also notice the three bleed screws |
Top side of the piston | | |