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To get your shocks to be as smooth as possible, you should always start out with a new shock rebuild kit (Associated part #6440) that has new spacers and new o-rings. I do not use a new kit every time I rebuild my shocks, but I usually replace the parts about every 3 weeks. You should also have a couple of clean rags along with some motor spray. If your shocks are old, it might be a good idea to get new shock shafts also. Unobtainium shafts are very good, but the stock shafts work just fine too. Assuming that you have a shock rebuild kit, take all the parts out of the bag and set the o-rings aside. Make sure you have a really sharp X-Acto knife or preferably a razor blade. Next, you will cut the parts off of the tree. When doing this, make sure that you leave no burs on the spacers and the locking washers. It is better to cut further into the part and take some extra material off of them than to leave any burs on. If you do leave burs on the parts, your shocks will not work correctly, nor will they assemble easily.
(If you are starting with new shocks that have never been run before, disregard the next step.)
Remove the shocks from the car and clean them off really well using a clean rag and motor spray if needed. Make sure you clean off the spring cups at the bottom also and the ride height adjusters as well. Getting everything clean will help to make the shocks smoother. Take the cap off and empty the oil then take the shafts out and also remove the seals and spacers from the bottom of the shocks bodies. You should clean the bodies and caps out using motor spray. Set the bodies aside to dry out.
Assembling the Shocks
Next you will assemble the seals/spacers. Put a generous amount of shock oil onto the shock assembly tool followed by the locking washer. Next, slide the first small spacer onto the assembly tool followed by the first o-ring, large spacer, second o-ring, and last small spacer. Then apply more shock oil to the whole seal assembly to make sure the o-rings are lubed well enough.
For shocks that have been used before make sure the area where the seals sit in the bodies is totally clean. Insert the seal assembly into the body of the shock and push down on the tool until you hear and/or feel a "click". Do not force the assembly in place, as it should be fairly easy to install. If it does not click, then you probably have some burrs on the edges of the spacers or locking washer and you will have to cut them off. Put the large o-rings on top of the bodies at the bottom of the threads.
It is a good idea to use new pistons every few months as they do get worn in and develop slop that affects the damping of the shocks. Put the pistons that you will be using on the shock shafts and apply oil to the threads of the shaft. Insert the shaft slowly into the body of the shock and pull it all the way through until the piston is against the bottom of the body. Wiggle the shaft around some to seat the seals and make sure everything is aligned correctly. Thread the shock ball end onto the shaft until it bottoms out.
Bleeding the Shocks
Holding the shock upright, slowly fill the body with oil until there is a slight dome of oil above the top of the body (fill it slowly to make sure that you get a minimal amount of air in the oil). Now move the shaft up and down slowly until you do not see any air coming out from beneath the piston. Thread on the shock cap until about a quarter of the threads are showing. Now push the shock shaft up into the body slowly until the shock end bottoms out against the bottom of the shock body. Thread the cap on the rest of the way (still holding the shaft in). You only want to tighten the cap FINGER TIGHT. No tighter. You should not need tools to assemble your shocks. When you let go of the shaft, it should rebound slightly, and when fully extended, it should suck back in slightly also. I suggest that you move the shaft in and out rapidly a few times to mix the oil and air so that the shocks will be more consistent. How far you push the shaft in depends mainly on the size of the shock body. For buggy front shocks, generally, you should push the shaft all the way in, for rear shocks, you should leave about 1/16 of shaft showing. This seems to work the best for me. You may have to vary how much shaft is showing between shocks on either side of the car depending on how much the shafts rebound so that both rear shocks are the same and both front shocks are the same. You can now assemble the rest of the shocks according to the instructions. When putting the springs on, make sure that they do not rub against the bodies when moved up and down. Rotate the springs to fix this if it happens.
Some say you should use Green Slime when assembling shocks. I do not believe you should. If you apply too much, it can get into the oil and possibly clog a piston hole. Also, the oil seems to be more consistent and doesn’t dry out like Green Slime seems to. I sometimes run 3 o-rings. This is to change the damping properties of the shock. Associated doesn’t make any ˝ weight oils (like 32.5), so running 3 o-rings provides enough friction to give the effect of running a 1/2 wt heavier oil. You should also measure the length of the assembled shocks to make sure they are equal side to side. Change the length by unscrewing the shock end of the short shock.