22 • X-MAXX
Once you become familiar with driving your model, you might need
to make adjustments for better driving performance.
Adjusting Gear Mesh
Incorrect gear mesh is the most common cause of stripped spur
gears. X-Maxx makes improper gear mesh virtually impossible. A
pin system helps set the motor in the proper place according to the
pinion and spur gear that are selected.
To access the pin system, remove the two 3x10mm screws that
secure the gear cover and remove the gear cover. Next, remove the
four motor mount screws from the bottom of the chassis and lift off
the motor. This will expose the pins. Be sure not to lose the pins that
go between the motor and the chassis.
Select the desired gearing from the
pin location chart. Replace the spur
and pinion gears as needed. When
installing the motor, install the pins
into their proper locations based on
the gearing that is chosen. The two
pins on the bottom help to lock the
motor into the proper place for correct
gear mesh. Secure the motor in place
with four screws inserted from the
bottom of the chassis.
Note:
Should you choose to do so, you can also set the gear mesh
manually without the pins. With the pins removed, use the four
4x16mm button-head cap screws on the bottom to set gear mesh.
Loosen the four 4x16mm button-head cap screws. Cut a narrow strip
of notebook paper and run it into the gear mesh. Slide the motor and
pinion gear into the spur gear. Tighten the four 4x16mm button-
head cap screws, and then remove the strip of paper. You should
be able to run a fresh strip of paper through the gears without
binding them.
Adjusting the Slipper Clutch
The model is equipped with an
adjustable slipper clutch that is
built into the large spur gear. The
purpose of the slipper clutch is to
regulate the amount of power sent
to the wheels to prevent tire spin.
When it slips, the slipper clutch
makes a high-pitch, whining noise.
To access the slipper clutch
assembly for adjustment or
removal, loosen and remove the
two 3x10mm cap screws from the
gear cover. Remove the gear cover.
Using the included wrench, make
the necessary adjustment to the
slipper clutch (B).
To remove the entire assembly,
loosen and remove the two
4x12mm button-head cap screws
and the two 4x30mm button-head
cap screws from the top shaft
cover. Remove the cover. The
entire slipper clutch assembly can
now be lifted out of the truck for
adjustment and inspection.
When removing the top shaft
assembly, be sure to inspect the
condition of the three bearings
in the slipper clutch assembly.
Ensure that they are spinning freely.
Replace the bearings if they are
showing signs of damage, wear, or
are not spinning freely.
Inspect the main input and output
gears for wear or debris in the
driveline. Clean and/or replace as
necessary. Occasionally inspect the
bearings in the center driveline to
ensure they are spinning freely.
Simply remove the upper bulkheads for access.
(Learn more about adjusting the slipper clutch in the sidebar.)
To achieve a good starting
point for the slipper clutch
in this model, remove the
slipper gear assembly from
your model (
see Adjusting the
Slipper Clutch
) and tighten
the slipper clutch adjusting
nut clockwise until the
slipper clutch adjusting
spring fully collapses (do
not over tighten), and then
turn the slipper clutch nut
counterclockwise 1/8 turn.
Do not run your model with
the slipper clutch adjusting
spring fully compressed. The
minimum recommended
slipper clutch setting is 1/8
turn counterclockwise from
fully compressed.
BASIC TUNING ADJUSTMENTS
A
B
Slipper Clutch Assembly Removal
3x10mm
CS
3x10mm
CS
4x12mm
BCS
4x30mm
BCS
4x16mm
BCS
