Traxxas 4-Tec 2.0 Owner'S Manual Download

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24 • TRAXXAS

7. Turn off the power to the model followed by the transmitter. The

servo horn is now ready to be installed.

8. Be careful not to move the servo shaft when installing the servo

horn. Readjust the ESC as described in the “Adjusting the Electronic
Speed Control” section.

Motors and Gearing

One of the more significant advantages to your model’s
transmission is the extremely wide range of available gear
ratios. It can be geared low enough to run an extremely hot,
modified motor. A higher kV motor should be geared lower
(higher numerically) than a stock motor because it will reach its
maximum power at higher rpms. A higher kV motor that is geared
incorrectly can actually be slower than a correctly-geared, stock
motor. Use the following formula to calculate the overall ratio for
combinations not listed on the gear chart:

If you are worried that you might be over-geared, check the
temperature of the battery pack and motor. If the battery is
extremely hot, and/or the motor is too hot to touch, your model is
probably over-geared. If you are not able to run your model for at least
four minutes before the battery dies, then change to a lower gear
ratio. This temperature test assumes that the model is close to factory
stock weight and operates freely with no excessive friction, dragging,
or binding, and the battery is fully charged and in good condition.

The model is equipped with a Velineon 3500 motor. The gear
combination that comes stock on each model provides good overall
acceleration and top speed. If you want more top speed and less
acceleration, install the included high-speed gearing (more teeth).
If you want more acceleration and less top speed, use a smaller
optional (not included) pinion gear.

The included high-speed

gearing is intended for high-speed running on hard surfaces, and
this gearing is not recommended for off-road or repetitive starting
and stopping.

For this type of driving, smaller pinion gears are

recommended to reduce load on the motor.

Tuning the Sealed Gear Differentials

The action of the model’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.

Your model will generally benefit from higher viscosity oil when
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 and the rear differential is filled with SAE
10,000W viscosity silicone 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 on the next page to access and refill the front and
rear differentials.

Gearing Compatibility Chart:
The chart below shows a full range
of gear combinations acceptable
for this model. This does NOT imply
that these gear combinations
should be used. Over-gearing
(bigger pinions, smaller spurs) can
overheat and damage the motor
and/or speed control.

# Spur Gear Teeth

x 2.85 = Final Gear Ratio

# Pinion Gear Teeth

ADJUSTING YOUR MODEL

Spur Gear

Pinion Gear

3.68

3.50

3.33

3.18

3.04

2.92