How to Get Your ride race-read Y
Differential and Slipper
You can quickly check the slipper by holding the
tires and trying to spin the spur gear, but it’s
better to spin it using the throttle. Power up the
vehicle, hold the tires, and goose the throttle. The
front end should come off your workbench about
an inch. If the front end comes up more than that,
you’re slipper may be set too tight; if it doesn’t
come up enough, the slipper is too loose or your
ball diff may be slipping. While holding onto the
spur gear, give a tire a spin and feel for grittiness
in the ball differential. If there is any, this is a sign
that the diff is set too loose and is slipping; you’ll
want to rebuild it. If it’s smooth, then you’re good
Give your tires a look to check for damaged or worn tread, and replace
them if necessary. Be sure to take the time to check the bond between
the tire and rim. Hold onto the rim and try to pull the tire away from it.
If the tire lifts off, then you’ll need to clean dirt out of that spot and add
some glue. Check all the way around, and make sure that you look at
both the front and back sides.
For the most part, the wires on your vehicle
are protected from the elements, but there’s
always a chance that they can shift and rub
against the drivetrain, suspension, or other
moving parts. That can rub the insulation off
the wires and possibly even cause a short.
Inspect all the wires to make sure that
the insulation is completely intact. Also,
examine the solder joints to make sure that
the wires remain properly anchored. Don’t
forget to check the sensor wires on your
brushless motor if you’re using one; they
can break at the connector.
To check the bearings, back the pinion gear away from the spur gear
and spin the drivetrain by turning the tires. If they spin freely, then your
bearings are good; if they stop right away, then a bearing is locked up
somewhere. It may take a while to find the bad bearing, but if you start
at the hubs (where the bearings see the most dirt and stress), you’ll
probably find the problem pretty quickly.
Spin the tires to make
sure that your bearings
are moving freely. The
front and rear hubs
are the most common
areas that have bearing
There’s always a chance that your wires may rub on
something that they shouldn’t. That can cause a short.
No matter how good your glue job is, you’ll always want to give the tire a tug to make sure
that it’s still properly secured to the wheel.
Hold onto the spur gear and spin a tire; this will quickly tell you
if you need a diff rebuild. If it feels gritty, chances are that the
diff has been running loose and has been slipping.