How to Build aluminum sHocks
The caps used to contain the
O-rings generally don’t have a way to get
a good grip and get them nice and tight.
Over time, they can loosen due to the
vibrations in your vehicle; this decreases
the pressure that the O-rings have on the
shock shafts and allows debris to get in
and possibly damage the seals and cause
oil to leak out, which will change how
your shocks perform. Before you install
the cap that retains the O-rings, clean
the threads and apply a small amount of
medium thread-lock; you can then install
the cap and tighten it. The thread-lock will
keep the cap from loosening, but you’ll still
be able to remove it later when performing
INSPECT THE PISTON
INSTALL THE SHOCK SHAFT
Make sure the piston is free of any
burrs or flashing that may interfere
with proper fit and smooth action inside the
shock. If your shocks arrived assembled,
inspect the e-clips or nuts that secure the
pistons before you put the shock shaft back
in the body. I found that some shocks have
loose nuts, and the e-clips can be loose if
not properly installed. The nut only needs to
be tight enough to prevent the piston from
moving up and down on the shaft; it’s OK if
the piston can turn. Tightening the nut firmly
against the piston may deform it, causing a
tight fit in the bore, which will bind the shock.
Before you install the shock shaft, make sure you install any necessary spacers
below the piston. If you forget, you’ll have to pour out the shock oil and take the shock
apart to install the spacers, which isn’t fun. Make sure the shaft’s threads have a good coating
of grease before you pass the shaft through the seals. Once the shaft is in place, you can clean
the excess O-ring grease off the threads and reinstall the rod end.
Medium thread-lock can be used on the
shock body to keep the O-ring cap tight
until you remove it for maintenance.
thread-lock for RC
Make sure that
the piston is
free of flashing
or burrs and is
on the shaft.
Before you put the shock shaft back in the
shock body, give the threads a light coat of
O-ring grease to help protect the seals.
Let the filled shocks sit
for about 10 minutes
after cycling the piston
to allow any air to work
its way out of the oil.
A shock stand, like this Duratrax Pit Tech
unit, is a big help when assembling shocks.
FILL THE SHOCKS
You now can fill the shocks with the oil of your
choice. I like to fill the shock body a third of
the way, then slowly move the piston up to the top of the
oil to get the oil under the piston and to get the air out.
Slowly move the piston back down, then you can finish
filling the shock body. Once the oil is at the top of the
shock body, wait about 10 minutes to let the air bubbles
work their way out.