It's All In THE
This is the one step that many just skip over, but it's here
where you'll gain results for a small amount of effort. Most
plastic parts are injection molded and that means flashing. In
shocks, flashing is the worst thing you can have on the spacers,
as it deforms, rips o-rings, and scratches shafts. Spending a
few minutes with a file or sandpaper will work wonders.
STEP 1: Remove the plastic parts from the tree. Some
parts have a certain way they are designed to be snapped off, to
reduce the amount of flashing from the edges of the pistons and
spacers. Pay attention, but if there isn't a pre-defined way to
do this, use an X-Acto knife and carefully remove all of the
parts required for the build.
STEP 2: A magnifying glass reveals wonderful things, and
in this case, the flaws. Under the glass, use a fine file like a
nail file, or some fine grit sandpaper, and remove all the
flashing from the spacers and pistons. You don't want to change
the shape of the part, but you want it to be smooth so it fits
into the space it was designed to fit into without deforming the
STEP 1: Install the piston on the shock shaft. Be sure to
keep in mind that the front shafts and bodies may be different
lengths than the rear. Keeping the pairs separate will avoid
STEP 2: Lay out the order of the o-rings and spacers in
front of each shock. Lubing the parts with oil will help things
go together easier and avoid tearing the o-rings. Team
Associated sells "Green Slime" which is used
in-between the o-rings and spacers to help eliminate air caught
in the spaces.
STEP 3: Lube the threads of the shock shaft and slowly
insert it into the body. This is a very critical part of the
process because the threads are usually still sharp, and they
can tear an o-ring if you're not careful. Slide the shaft all
the way down to the bottom of the body. Repeat this for each
STEP 4: This step can be done last, but I like to get it
out of the way early. Attaching the shock end is something that
is more difficult than it seems. Lots of shocks have such a
tight fit and hard plastic that it's hard to get a grip on the
shaft. I use wire cutters to grab the last thread on the shaft.
Unless it's a cheap shock, you can really put some force on the
cutters to hold the shaft as you thread the end on.
STEP 5: Pull the shock shaft all the way out.
STEP 6: Fill the shock with oil. Tilt the shock on an
angle to avoid getting air bubbles in the oil. Fill it to the
top of the shock or just slightly below.
Here's where the "hard" part happens. Filling the
shocks with oil is easy, but it's also easy to add too much or
not enough, and this will alter the performance and consistency
of the shock, possibly throwing the car out of balance. The next
steps are specific for bladder and emulsion-style shocks. There
are only a few differences in building the shocks, and this is
noted where applicable.
Emulsion, by definition, means one liquid is suspended in
another, and in shocks that's air and oil mixed together in a
"frothy" like mixture. Because the oil and air are
not separated, as in a bladder system, the volume needed to
allow full stroke of the shock is found in the oil. As the
shaft enters the emulsion, the air is forced to the sides and
the shaft has room to enter. This also slightly affects
damping, as air will slightly lessen the thickness of the oil.
Therefore, to really check damping, you have to pump the shock
vigorously to get the consistency of the emulsion to race
STEP 7A: Wait. Here's when waiting a few minutes pays
off. Slowly pump the shocks to try and get all the air that may
be trapped under the piston out of the oil and to the top. If
you can get the shocks to fit in the Ride Shock Pump, this will
speed the process (see sidebar). Otherwise, after pumping the
shocks a few times, letting each one sit will allow most of the
air to float to the top. Thicker oils will take longer.
STEP 8A: Place the bladder on the shock and press on the
edges. You're trying to bleed some of the oil out of the body,
but not create any bubbles.
STEP 9A: Put the cap on and tighten the cap all the way
down. Remember to use any o-ring around the cap.
Bladder-style shocks are ones that use a rubber diaphragm to
separate the air from the oil. During compression the air at
the top is compressed to allow the shock shaft the volume to
enter the shock. If too much oil is used there won't be enough
airspace to allow the shock to function properly, and the
damping rate is altered. This separation is more consistent
than the non-bladder because of the separation of air and oil.
STEP 7B: Insert the cap or bottom-loading cartridge, and
tighten it almost entirely. At this point you need to bleed out
the excess oil, and leave enough air in the body to allow room
for the volume of shaft.
STEP 8B: While the shaft is fully depressed, tighten the
STEP 9B: This is where emulsion shocks will differ. By
their design you should hear air in the shocks when you pump
them. Pump them several times to get the air and oil mixed (emulsified),
then test to see if there's the correct amount of oil mixed (emulsified),
then test to see if there's the correct amount of oil in the
shocks. Press the shock in and feel for resistance. The shaft
should be able to be pushed all the way in and rebound slowly
STEP 10: Check oil level by pressing the shock shaft all
the way in the shock body. There should be no air in the oil. To
check this, listen to the sound of the oil. If it's filled
correctly you shouldn't hear air in the oil. If there's too much
oil, the shaft will resist being pushed in all the way and will
snap back at you.
STEP 11: Measure the shock lengths to ensure that they
are built to the same length. Adjust shock end if necessary.
STEP 12: Complete the shocks using the remaining items
that are shock specific. Put the spring retainers on the body,
insert the spring, and finally add the spring perch to the
When you repeat this process four times--or eight times if
you've got one of the trucks that uses double the
pleasure--you'll end up with some super smooth and consistent
shocks. After you build more than a few shocks, you may even
learn to love the art form of building shocks.