SLASH 4x4 • 27
TUNING THE SEALED GEAR DIFFERENTIALS
The action of the Slash 4x4’s front and rear gear differentials can be
tuned for different driving conditions and performance requirements
without major disassembly or removal of the suspension system.
From the factory, the differentials are sealed to maintain consistent
long-term performance. Changing the oil in the differential with
either lower or higher viscosity oil will vary the performance
characteristics of the differentials. Changing to a higher viscosity oil
in the differential will reduce the tendency for motor power to be
transferred to the wheel with the least traction. You may notice this
when making sharp turns on slick surfaces. The unloaded wheels
on the inside of the turn have the least traction and tend to spin
up to extremely high rpms. Higher viscosity (thicker) oil causes the
differential to act like a limited-slip differential, distributing more
equal power to the left and right wheels.
Slash 4x4 will generally benefit from higher viscosity oil when
climbing or racing on low traction surfaces.
Note
: Heavier oil will
allow power to be transferred even with one or more tires off the
ground. This can make the vehicle more likely to overturn on high-
traction surfaces.
From the factory, the front differential is filled with SAE 30,000W
viscosity silicone oil. The rear differential is filled with grease, but can
also be tuned with silicone differential oil.
Only use silicone oil in the differentials. Traxxas offers SAE 10,000W,
30,000W, and 50,000W viscosity oil (see your parts list). The
differentials have to be removed from the vehicle and disassembled
to change/replace oil.
Follow the steps below to access and refill the front and rear
differentials:
Front differential:
1. Remove the two 3x15mm button-head screws that secure the
top bumper mount to the differential
(
diff) case.
2. Turn the chassis over and remove the three 4x10mm countersunk
screws that hold bumper/skid plate to the bulkhead. The two rear
screws do not need to be removed.
3. Slide bumper assembly off of the chassis.
4. Remove 3x15mm button-head screw from diff tie bar.
5. Slide tie bar off truck.
6. Remove two 3x15mm button-head screws from diff cover.
Do not remove the two screws that secure the shock tower.
7. Use a 1.5mm hex wrench to remove the two screw pins that
hold the driveshaft yokes to the differential output shafts.
Remove the differential cover and slide the differential out of the
front of the case.
8. To reinstall the differential, reverse the steps.
ADVANCED TUNING ADJUSTMENTS
1.
3x15 BCS
4.
3x15 BCS
6.
3x15 BCS
2.
4x10 BCS
3.
Front Differential Removal
5.
