Off-road Suspension Tune-up
Words: Nick Malato
steps to de-slop and smooth out your suspension system
In off-road racing, your car or truck is only as good as its
suspension, and all the suspension components get a heavy workout each
time you hit the track. Neglect your machine, and it wonít be long
before performance suffers noticeably. But itís never too late to
get your car back up to spec. Just follow these steps, and your
suspension will be swinging like its old self again.
easier to inspect the suspension when the parts are clean and
the wheels and shocks have been removed.
Strip the car down to get to the suspension. Remove the
body and tires, the shocks and even the tie rods. Next,
clean the suspension parts with a toothbrush and
compressed air. Get all the dirt out of the works. A
good cleaning gives you the opportunity to look at all
the parts of the suspension to make sure that nothing is
cracked, bent, or worn out. Replace any parts that look
questionable; itís better to do it now than waste time
at the track.
each arm and release; it should fall under its own
weight. If it doesnít, start wrenching.
for free movement
Make sure that all the suspension arms move
freely through their complete range of motion.
The arms and uprights should drop under their
own weight. Suspension arms that bind or donít
move properly can cause handling problems when
you hit the track. But also make sure that they
donít move too freely: they should swing up
and down easily but not have excessive free play
on the hinge pins. If the arms wobble on the
hinge pins, itís generally best to replace
them. If there is extra room on your hinge pin
between the arm and the E-clip, itís a good
place to put a couple of motor washers. These
washers can take up the slack so the arm wonít
slide back and forth.
a pin may look straight, but the roll test will
help you to spot when itís slightly bent.
Right: pitted or rusty hinge pins are easily
revived with a little metal polish.
up Tight Hinge Pins
the arms do not move freely, remove the
hinge pins and check whether they need
to be cleaned or replaced. Roll your
hinge pin on a flat surface; if it
wobbles, itís obviously bent. Bent
hinge pins will bind and wonít allow
the suspension to move freely. Dirty or
rusted pins can also cause hang-ups. Put
a dab of metal polish on a rag, and use
a rotary tool or a power drill to spin
and polish the pin. Use the slowest
setting, and be careful not to get the
rag caught in the chuck of the tool.
piece of plastic bag under the ball cup (left)
or an O-ring over the ball stud (right) will
tighten a loose ball cup.
The ball-cup fit
Your vehicleís ball cups should
operate freely but with as little ďslopĒ
as possible. If your ball cups have a
lot of play, they wonít be able to
hold precise camber and toe settings. If
that sounds like your car, itís best
just to replace the cups, but that isnít
the only fix. You can shim the cup by
placing a piece of plastic bag over the
ball and snapping the cup over it. Some
bags are thicker than others, so you
might have to experiment to get the
perfect fit. Or you can slip an O-ring
over the ball stud before you snap the
ball cup onto it. Just make sure that
the suspension still moves freely, as
described in step 2.
Excessive wetness around the seals
means itís time to rebuild.
Shaft should be shiny, not scuffed.
the shaft straight?
Remove the shock springs so you
can get a good look at the seals
and shafts. Obviously, a bent
shaft should be replaced, but
even a straight shaft should be
replaced if itís heavily
scuffed. A shiny shaft seals
better, wears the seals less and
operates with less drag. Take a
good look at the bottom of the
shock; if itís wet with fluid,
the seals should be replaced.
Last, compress the shock shaft.
The piston should move smoothly
throughout its travel range. If
you feel any tight spots, check
the shock body for dents, and
have another look at the shaft
to be sure it isnít bent. If
the shock seems to operate
smoothly but you feel air
bubbles in the fluid, pump the
shock shaft. If the air
emulsifies in the fluid, the
shock will smooth out. If you
still feel the bubbles in the
piston stroke, it means there
isnít enough fluid in the
shock. Refill the shocks with
fresh fluid; donít just top
spoke with Team Losi driver Todd Hodge
for his factory suspension tips.
RC Car Action: Do you
rebuild your cars or trucks for a big
event or run brand-new ones?
Todd Hodge: I like to
rebuild my cars. This way, I am totally
familiar with the car. I find when I do
run a new car, it takes a good day of
running it to get acclimated to it. At a
national or regional event, you donít
have a day to waste.
RCCA: Do you build
several spare sets of shocks, each with
different setups to try?
TH: I try not to. In
the past, Iíve tried two or three
setups, and I just end up wasting time
testing all of them instead of getting
used to driving the car. Lately, Iíve
just run my races without overly
wrenching to get used to the track. This
is one thing Ryan Cavalieri does ... he
never changes his car. He practices lap
after lap and learns how to dissect the
track and find the fastest way around
RCCA: What sort of
shock maintenance will you do during a
day of practice at a national event?
The shocks are important and require the
most attention. All of the silicone oils
we use tend to make the O-rings in the
cartridges swell, so I usually change
those every day at a big event, or every
other day depending on how dusty the
track is. If itís really dusty, then
you should rebuild the cartridges every
day. I also check my bearings to make
sure they are free, and I clean out my
ball cups with a Q-Tip and some Simple
Green to ensure free movement.
RCCA: At the Worlds,
some guys completely rebuilt their cars
the night before qualifying. Is that
standard practice, or just for the
TH: Many racers tend to
go overboard. I think as long as you
make sure that all the carís bearings
and hinge pins are clean and the
suspension moves freely, everything will
be fine. In the 4WD class at the Worlds,
it rained during practice, so it was a
must to tear your whole car down to
clean it, since it was caked with wicked
RCCA: Any final tips?
practice, practice. Many of the topnotch
racers arenít there simply because
theyíre talented. They also practice
and race as much as they can. Also, itís
important to pay attention to details
and be meticulous when building your