Traxxas 1/16 SLASH VXL 4WD 7108 - Manual (Page 21)

TR A X X AS • 21
TUNING ADJUSTMENTS
The Slash VXL 4WD and E-Revo VXL are factory-tuned for optimum
performance in a wide variety of off-road conditions. To tailor the
performance and handling of your model to suit your driving style and
terrain, both models have a number of adjustable features. Gearing,
shock preload and damping, ride height and wheel camber can all be
easily adjusted.
SUSPENSION TUNING
Ride Height Adjustment
The Slash VXL 4WD and
E-Revo VXL both have
threaded shock bodies
that make it easy to adjust
ride height. Threading the
shocks’ preload collars
away from the caps will
raise the vehicle’s ride
height (the distance
from the chassis to the
ground), and reduce the
suspension’s down travel,
also known as ‘sag’ or
‘droop’. This can be helpful in rugged terrain where extra ground
clearance is needed. However, the vehicle’s center of gravity (CG) will
be raised, making it less stable.
Threading the shocks’ preload collars toward the caps will lower the
vehicle’s ride height and increase the suspension’s droop. This will
lower the vehicle’s CG and improve handling, but it will also reduce
ground clearance.
From the factory, Slash VXL 4WD and E-Revo VXL are set up as shown
in the illustration above. At rest, the suspension sags to about 1/3
of its total travel. This allows the suspension to extend so the wheel
can drop into depressions over rough terrain. This leaves 2/3 of the
total suspension travel for compression when absorbing bumps and
landing jumps. These settings are ideal for most surfaces, and only
small changes in ride height should be required to fine-tune the
vehicle’s handling for your particular surface.
Shock Oil
The 4 oil-filled shocks (dampers) effectively control the suspension
movement by preventing the wheels and tires from continuing
to “bounce” after rebounding from a bump. Changing the oil in
the shocks can vary the suspension damping effect. Changing the
oil to a higher viscosity oil will increase damping. Lowering the
viscosity of the oil will cause the suspension damping to be reduced.
Damping should be increased (with higher viscosity oil) if the model
is bottoming easily over jumps. Damping should be decreased (with
thinner viscosity oil) if the model is hopping over small bumps and
feels unstable. The viscosity of shock oil is affected by extremes
in operating temperature; an oil of certain viscosity will become
less viscous at higher temperatures and more viscous at lower
temperatures. Operating in regions with cold temperatures may
require lower viscosity oil. The Slash VXL 4WD’s shocks are filled with
SAE 30W oil. The E-Revo VXL’s shocks are filled with SAE 40W oil. Only
use 100% silicone oil in the shock.
Replacing Shock Oil
The shocks have to be removed from the vehicle and disassembled to
change the oil.
1. Remove the lower spring
retainer and shock spring.
2. Remove the upper shock
cap. If you cannot unscrew
the cap with your fingers,
pass the 2mm ‘L’ wrench
through the cap’s eyelet
so you can apply more
leverage. Turn the cap counterclockwise to loosen it.
3. Empty the used shock oil from the shock body.
4. Fill the shock with new silicone shock oil up to the top of the
shock body.
5. Slowly move the piston up and down (always keeping it submerged
in oil) to release the air bubbles. Let the shock sit for a few minutes
to allow any remaining air bubbles to surface.
6. Slowly thread the upper cap with the installed shock bladder onto
the shock body. The excess oil will bleed out of the small hole in the
shock cap.
7. Tighten the shock cap until snug.
Compression 2/3
Sag (Droop) 1/3
Ride Height
To
ta
l T
ra
ve
l
Axle Centerline at Ride Height
Axle Centerline at Max Compression
Axle Centerline at Max Sag
Important: The shocks are
assembled at the factory with
a center-to-center distance
(between the rod end balls)
of 47.75mm. Any time the
shocks are removed and
disassembled, this distance
should be checked to ensure
proper operation of the
suspension.
47.75mm