Traxxas 4801 User Manual

ASSEMBLY MANUAL,

TUNING GUIDE

MODEL 4801

INTRODUCTION

Thank you for purchasing a Traxxas Nitro 4-Tec Pro.
This limited-edition, pro kit is loaded with all the latest
sedan racing hardware and engineering technology.
This pro kit does not come with an engine or tuned pipe,
allowing you to choose an engine which is legal for your
race track. If racing regulations do not limit you to a .12
size engine, then install the TRX Pro .15 engine for fast,
asphalt-blistering excitement.

The Nitro 4-Tec Pro features
dual adjustable pro ball differentials smoothly distribute
the power to each corner of the car. Handling is quick
and precise with fully-independent suspension and tune­able, oil-filled, pro-level, aluminum Big-Bore shocks.
Nitro 4-Tec Pro kit includes a two-speed, auto-shifting
transmission; full ball bearings; Lunsford™ titanium hinge
pins and turnbuckles; Perfect-Fit™ blue-anodized, aluminum
header; Pro-Line™ V-Rage™ tires; 2.0” aluminum finish,
mesh wheels; and graphite chassis components.

While it is possible to assemble your model just by fol­lowing the pictures, please read the text next to each
photo. The text contains important information you need
such as screw sizes or assembly tips.

ADDITIONAL COMPONENTS

You will need these important components to complete
this kit:

•Engine
wo-channel radio system

•T

•Tuned pipe

•Engine Fuel & dispenser

•Body (200mm)

NOTE:The Nitro 4-Tec Pro is designed to use a .12­.15, side-exhaust, short crankshaft engine with back­plate (requires starter box) or pull starter. Some wider
pull starters, such as O.S. and clones, will not fit.

This manual covers the assembly and tuning process
for the Nitro 4-Tec Pro kit. Look over this entire manual
and examine the Nitro 4-Tec Pro carefully before
assembling it. If for some reason you think the Nitro 4­Tec Pro is not what you wanted, then do not continue
any further. Your hobby dealer absolutely cannot accept
a Nitro 4-Tec Pro kit for return or exchange after any of
the kit bags have been opened. If you have any ques­tions about your new Nitro 4-Tec Pro, call Traxxas’ tech­nical support department at (888)TRAXXAS (U.S.A. res­idents only). Outside U.S.A. call 972-265-8000.
Technical support is available Monday through Friday,
from 8:30 AM to 5:30 PM Central Time. You may also e­mail us at our website, www.Traxxas.com. We hope that
you will enjoy your Nitro 4-Tec Pro race car.

ASSEMBLY HINTS

To assemble this kit, you’ll need a large flat working area
where you will have plenty of room to build. Be sure it is
some place where you can leave your work spread out
and not in the way when you want to take a break from
the assembly. Allow yourself plenty of time to build this kit.
The assembly time is going to vary with each individual.
Experienced builders may only need 4 - 5 hours to assem­ble this kit, while others may spend an entire weekend on
it. You should feel comfortable with taking as much time as
you need to properly build and set-up your model. The
race, after all, is on the track, not the workbench.

TOOLS YOU WILL NEED

Some of the tools which you will need to assemble this
kit have been provided for you, they include:

1.5mm hex wrench

2.0mm hex wrench

4-way wrench
U-joint assembly tool

2.5mm Hex wrench

Turnbuckle wrench

To complete your kit, you will need some basic hand
tools such as:
small hammer
#1 Philips screwdriver
#2 Philips screwdriver
Flat blade screwdriver (.25 inches wide)
Channellock™ pliers
Needlenose pliers
Hobby knife
Small, flat-blade, jeweler’s screwdriver
Thread-locking compound, such as Locktite™

The tools and accessories pictured are also necessary
for correct assembly.

If you have already been exploring the contents of
your kit box, you’ve noticed that there
are many bags of small
parts. A parts box has
been provided with your
kit to keep all of these
small parts organized and
easily accessible. As you
open a bag of hardware,
use what you need and
pour the remainder in one of the compartments.

The
compartments are labled in procession with the assembly
step numbers. Some extra hardware may be left over
when the car is assembled.

2

3mm Tap

CA Glue

60-WT Silicone

Shock Oil

Metric Hex Drivers

Snap Ring Pliers

WARRANTY STATEMENT

3x6x4mm Spacer

4mm

3mm6mm

12mm

3mm

3x12mm Countersunk

machine screw

12mm

3mm

3x12mm Roundhead

machine screw

Countersunk Cap Screw

Buttonhead Cap Screw

Shoulder Screw

Countersunk Self-tapping Screw

Washerhead Self-tapping Screw

Roundhead Self-tapping Screw

Nylon Locknut

Flange Nut

Grub Screw

Plastic Bushing

Aluminum Spacer

Plastic Washer

Metal Washer

Split Washer

E-Clip

Oilite Bushing

Every effort has been made in component design and
material selection to make your model as durable as
possible and still maintain a competitive race weight.

Because this model is intended for use in high speed
competition under the most severe conditions, no war­ranties are expressed or implied relating to the longevity
of the parts.

If you find a part that has a defect in materials or work­manship, please return it to us BEFORE IT IS USED,
and we will gladly replace it.

Damage caused by crash damage, excessive force,
abuse, neglect, or failure to adhere to the precautions
outlined in the literature contained with your model will
void the warranty.

HARDW

The drawings that follow are provided to help you identi­fy the many different sizes and types of hardware you
will be using as you assemble this kit. Note the differ­ence between the length measurements of the round­head and countersunk screws. A ruler is provided at the
bottom of each page to measure the length of the screws
in millimeters.

ARE DESCRIPTION

PTFE Washer

CENTERING THE SERVOS

The kit version does not include the radio system. The
photos in this manual do show the installation of a typical
radio system. Before installing the radio system, find the
center neutral position of the steering and throttle servos.

Connect the radio system according to your manufacturer’s
instructions. Install fresh batteries. Turn on the transmitter
and receiver. Set the throttle and steering trims to their
neutral positions. Now turn off the receiver, followed by
the transmitter. Be careful not to turn any of the servo
output shafts during installation.

3

PERSONAL SAFETY PRECAUTIONS

.25¨ (6mm)

Left side frame

Right side frame

Rear of car

Rear of car

T

i

g

h

t

e

n

T

i

g

h

t

e

n

Increasing

rear belt

tension

Please follow the precautions at all times. Operate your
Nitro 4-T

ec Pro sensibly and with care and it will be
exciting, safe, and fun for you and your spectators.
Failure to operate your Nitro 4-T

ec Pro in a safe and
responsible manner could result in property damage and
serious injury. You alone must see to it that the instruc­tions are followed and the precautions are adhered to.

NOTE: Nitro 4-Tec Pro gear ratios must be changed
as 1st and 2nd gear sets in order to maintain com­patible gear center distances. The gear ratio chart
gives the only four compatible ratio choices.

GEAR CLUTCH SPUR PRIMARY OVERALL SPEED

OPTIONAL CLUTCH GEARS 1st ........16 ........41 ........2.5 ............5.81 ...........37.3

w/OPTIONAL SPUR GEARS

tio Characteristics: Moderate acceleration, highest top speed

Ra
Recommended

Application: Sport/recreational running in very large areas

TEETH TEETH REDUCTION REDUCTION (EST. MPH)

2nd ........20 ........37 ........1.85 .........4.19 ...........51.6

The Nitro 4-Tec Pro is not intended for use by children
without the supervision of a responsible adult. Every
precaution outlined in this manual should be followed to
help ensure safe operation. Traxxas Corporation shall not
be liable for any loss or damages, whether direct, indirect,
special, incidental, or consequential, arising from the use,
misuse, or abuse of this product and any chemical or
accessory required to operate this product.

• The fuel is dangerous and poisonous. Follow all of the

direction and precautions on the fuel container.

• The fuel can look like a cool drink to a young child.

Keep it out of children’s reach.

• The fuel is flammable. Do not allow sparks, flame, or

smoking in the presence of model fuel.

• The engine emits poisonous carbon monoxide gas just

like a real automobile engine. Always run the model in a
well-ventilated area. Never attempt to run the engine
indoors unless there is adequate ventilation.

• The engine and exhaust system become extremely

hot during use. Be careful not to touch these parts, espe
cially when refueling.

• Do not drive the Nitro 4-Tec Pro at night.

• Never, under any circumstances, operate the Nitro 4-Tec

Pro in crowds of people. The model is very fast and
could cause injury if allowed to collide with anyone.

• Because the Nitro 4-Tec Pro is controlled by radio, it

is subject to radio interference from many sources that
are beyond your control. Since radio interference can
cause momentary losses of radio control, always allow
a safety margin in all directions around the car in order
to prevent collisions.

• The engine can be very loud.If the noise makes

you uncomfortable, wear ear protection. Be considerate
of your neighbors by not running your model early
in the morning or late in the evening.

• Most importantly, use good, common sense at all times.

GEAR RATIOS

Another Nitro 4-Tec Pro feature is the ability to change
the gear ratios. Currently
ratios for the Nitro 4-T
provide the best acceleration.
gear ratio provides extreme top speed

, there are three optional gear

ec Pro.

The stock gear ratio will

higher (lower numerical)

A

primarily intend­ed for flat-out running on large, unobstructed, paved
areas. Organized, 1/10 scale, nitro touring car racing is
typically done on smaller
racing use a lower (higher numerical) gear ratio such as

, closed courses. For this type of

the stock gear ratio. The following chart gives the four pos­sible gear ratios sets. The ratios are arranged from highest
(lowest numerical) to lowest (highest numerical).
application recommendation follows each gear ratio set.

A

brief

STOCK CLUTCH GEARS 1st ........15 ........41 ........2.73 .........6.20 ..........34.9

w/OPTIONAL SPUR GEARS 2nd ........19 ........37 ........1.95 .........4.41 ..........49.0

Ratio Characteristics: Good acceleration, very high top speed
Recommended

OPTIONAL CLUTCH GEARS

w/STOCK SPUR GEARS 2nd ........20 ........41 ........2.05 .........4.65 ..........46.6

Ratio Characteristics: Very good acceleration, high top speed
Recommended Application: Sport/recreation, racing on large 1/8 scale size tracks

NITRO 4-T
EQUIPMENT

tio Characteristics: Explosive acceleration, moderate top speed

Ra
Recommended Application: Racing on small, tight tracks.

Application: Sport/recreation running in very large areas

1st..........16 ........45 ........2.81 .........6.38 ..........34.0

ec PRO STOCK 1st..........15 ........45 ........3.00 .........6.80 .........31.8

2nd ........19 ........41 ........2.16 .........4.89 .........44.3

Recreational running in small areas.

BELT TENSION ADJUSTMENTS

The rear belt tension is adjustable via belt tension cams in
the right and left rear side plates. The rear belt in the Nitro
4-Tec Pro transmits most of the engine’s power. Because
of the high loading of the rear belt, the tension should be
checked every 3-4 hours (20-25 tanks of fuel) of running.
If the rear belt can be deflected more than 0.25¨ (6mm)
(see drawing), the belt tension cams should be rotated
rearward to the next eccentric slot.

s front and middle drive belts are

The Nitro 4-T

ec’
designed to have a high initial tension. During the break­in period, the drive belts and pulleys will “wear in” and
the belt tension will gradually decrease. The front and
middle belt tensions can be tightened by inserting
3x6x.5 flat metal washers under the front bearing block
spacers. Do not tighten the front belt tension unless
there is more than 0.25 inch (6mm) deflection at the
center of the belt (see drawing).

4

SHIFT POINT ADJUSTMENT

The Nitro 4-Tec Pro comes equipped with a two-speed
transmission.

When the shift point on this transmission is
adjusted correctly, it will maximize acceleration, improve
drivability, and minimize lap times. Use a 2.0mm allen
wrench to adjust the shift point.

NOTE: It is important that your engine is properly
tuned and has reac

hed full operating temperature
before making shift point adjustments. Stop the
engine before making adjustments.

1) Stop engine.

2) Rotate the drum until the access hole is visible from

the top.

3) Hold the spur gear set, and roll the car forward while

looking through the access hole. Note that you will see
two set screws through the access hole as you roll the
car forward. The first one holds the two-speed mecha­nism to the shaft. Do not loosen this screw unless you
want to remove the two-speed mechanism. The second
is the adjustment set screw. Refer to the drawing to
identify the screws.

4) Insert a 2.0 allen wrench through the clutch drum and

into the adjustment set screw. (See diagram)

5) Turn the adjustment screw clockwise to raise the shift

point (later shifts).
Be careful not to
overtighten the
adjustment screw or
you may damage the
tension spring.

6) Turn the adjustment

screw counter-clock

­wise to lower the shift
point (earlier shifts).
Be careful not to
loosen the adjustment
screw too much or
you may cause the
screw and spring to
fall out.

1

7) Use

/8-turn increments
to find the approximate,
desired shift point.

8) Check performance by running a test lap after each
adjustment.

1

9) Use

NOTE:The transmission ma

/8-1/16turn increments to fine tune the shift point.

y not shift if the adjust

-

ment screw is turned too far in (locked in first gear),

or too far out (locked in second gear). If the car has
quick acceleration and does not appear to shift, the
transmission is never reaching the shift point.The
shift point needs to be lowered by turning the
adjustment screw counter-clockwise. If the car has
poor acceleration but very high top speed, the
transmission

is shifting into second gear almost
instantly. The shift point needs to be raised by turn­ing the adjustment screw clockwise.

TOE IN

The Nitro 4-Tec Pro is supplied with soft-compound,
race-quality tires. Due to the high power output of the
Pro-15 engine and the high performance nature of the
tires, suspension alignment is critical to achieving maxi­mum tire life. Proper alignment promotes even and con­sistent tire wear as well as predictable and balanced
handling. Set the steering trim on your transmitter to
neutral. Now, adjust your steering turnbuckles so that
both wheels are pointing straight ahead and are parallel
to each other (0 degrees toe-in). This will ensure the
same amount of steering in both directions.

CAMBER

The camber angle of both the front and rear wheels can
be adjusted with the camber rods (upper turnbuckles).
Use a square or right-angle triangle to set the camber
accurately. Adjust the front wheels to 0 degrees of cam­ber (wheel is perpendicular to the ground). In the rear,
adjust the wheels to 1 to 2 degrees of negative camber.
These adjustments should be set with the car positioned
at its normal ride height.
The following information gives recommended stock
alignment settings for the Nitro 4-Tec with stock tires
and inserts.

NEGATIVE CAMBER

POSITIVE CAMBER

• Front Camber Degrees ....-1.0

• Rear Camber Degrees ....-1.0

12.0

• Front Caster Degrees*

oe-In Degrees ........0.0

T

• Front

....

* This setting is achieved by having the 1mm caster
spacer in the front and the 2mm caster spacer in
the rear (where the upper suspension arm attac

hes

to the upper suspension arm mount).

5

SHOCKS

SPRING SPECIFICATIONS

The four shocks on your Nitro 4-Tec Pro have the most
influence on its handling. Whenever you rebuild your
shocks, or make any changes to the pistons, springs or
oil, always do it carefully and in pairs (front or rear).
Piston head selection depends on the range of oil vis­cosities that you have available. For example, using a
one-hole piston with a lightweight oil will give you the
same dampening as a two-hole piston with heavier oil.
We recommend using the two-hole pistons with 60W oil
(available from your hobby shop). The thinner viscosity
oils (30W or less) flow more smoothly and are more con­sistent, while thicker oils provide more dampening. Use
only 100% pure silicone shock oil to prolong seal life.

Front and rear black springs (included):

Coils: 6.0
Wire Diameter: 1.18mm, (0.046in)
Inside Diameter: 13.6mm, (0.54in)
Height: 26mm, (1.0in)
Rate: 136 kg/m, (122 oz./in/), (7.6 lb./in)

MAINTENANCE

Form the habit of visually inspecting the mechanical
integrity of the Nitro 4-T

ec Pro before each run.

1) Check the wheels and steering for binding. Check the

operation of the shock absorbers.

2) Check the tightness of the grub screws in the collars

on the throttle and steering linkages.

3) Check the mounting of the receiver and servos.

4) Check the tightness of the wheel nuts with a wrench.

5) Check the fuel tank and all hoses for signs of leaks.

6) Check the operation of the radio system, especially the

condition of the batteries.

7) Check the exhaust system for leaks, cracks, or tears.

Do not run the car if there are any exhaust leaks.

8) Use Traxxas Nitro Wash spray cleaner to keep the

Nitro 4-Tec Pro clean of accumulated dirt and oil.

The ride height for Nitro 4-Tec Pro can be adjusted by
adding or removing the clip-on spring pre-load spacers.
Instead of adding spacers to increase stif

fness, use
stiffer springs. Adjust the ride height so that the suspen­sion arms are parallel to the ground. Note that changes
in ride height will occur when the changes in damper
angle or spring rates are made. You can compensate for
ride height changes by changing the pre-load spacers
on the dampers. Generally speaking, ride height should
be set as low as possible without causing significant
bottoming of the chassis. Also, in order not to disturb
cornering balance, front and rear tire height diameters
should be equal. Replace excessively worn tires.

NOTE: At no time should the body of the car strike
the

gr

ound or interf

ere with the suspension or tires.
Either situation will cause extremely unpredictable
handling.

For technical assistance regarding your model,
inside the United States, call 1-888-TRAXXAS.
For orders outside of the US and other information,
call 972-265-8000.
www.Traxxas.com

Traxxas
1100 Klein Rd.
Plano, TEXAS 75074

6

N4T Pro Assembly Procedure:

1) Assemble dampers and springs per the instructions. Dampers should
be 65.5mm overall when assembled. Set aside. Bag A

A-1

Remove the shock parts from Bag A. Pour the contents of each individ­ual bag into the corresponding compartment of the plastic parts box.

A-2

Insert a 6x.7mm clear spacer into the bottom of the aluminum shock
body.

A-3

Take a blue O-ring and push it into the bottom of the shock body.

A-4

Find one of the white 3x6x2.5mm white PTFE
spacers and carefully remove any mold flas
with a hobby knife. Insert the spacer into the
bottom of the shock body and press firmly so
that it compresses the blue O-ring.

Insert a blue O-ring and press it against th
white PTFE spacer.

e

A-5

Locate one of the 3x7.5x.8mm translucent seals and insert it into the
shock body. Press it down firmly until the groove on the inside edge of
the shock body is visible.

hing

7

STEP A-6

Secure the bottom shock assembly with a C-clip. Use C-clip pliers to
compress the C-clip and and insert it into the groove in the bottom of the
shock body. If you do not have any C-clip pliers or strong, sharp tweez­ers, try inserting one side of the C-clip into the groove and then carefully
push the other side into the groove with a small screwdriver. Wear pro­tective eyewear when working with the C-clips.

STEP A-7

Locate one of the 32mm shock shafts and snap a small E-clip into the
bottom groove on each.

STEP A-8

O-Rings

hole

molding
indention

molding
indention

hole

Find one of the two-hole piston heads and place it onto the shaft. The
picture shows two holes and two molding indentations. The holes are all
the way through the piston head.

STEP A-9

Secure the piston head with a small E-clip

STEP A-10

Locate the two blue O-Rings. Slide the O-rings over the grooved end of
the shaft. These are shock travel limiters.

8

STEP A-11

Place a drop of 60WT shock oil on the threaded end of the shock shaft
and insert it into the shock body. Carefully push the threaded part of the
shaft past the seals in the bottom shock assembly.

STEP A-12

Slide a blue O-ring over the end of the shock shaft. This O-ring acts as
a bump stop.

STEP A-13

Locate one of the 4 short nylon rod ends. Grip the shock shaft with
needlenose pliers just above the threads. Do not grip the shaft with the
pliers in the middlle part of the shaft, where it will contact the internal
shock seals. Scarring on the shaft will damage the seals. The Screw the
short rod end onto the shaft until it stops or all the threads are con­cealed.

STEP A-14

Find one of the 4 aluminum shock caps and a rubber diaphragm. Insert
the diaphragm into the shock cap with the dome facing outward. Use a
small tool to press the edges of the diaphragm flat in the shock cap.

STEP A-15

Place a drop of oil into the shock cap to lubricate the edges of the rubber
diaphragm. This will prevent damage to the diaphragm when it it is tight­ened against the shock body

.

9

STEP A-16

Pull on the shock rod so that the piston head travels to the bottom of the
shock body. Fill the shock with 60WT oil until it is about 3/4 full. Slowly
move the piston up and down to remove any air bubbles. If necessary,
allow the shock to stand until all the bubbles rise to the top. Fill the
shock until the oil level is about 1mm from the top edge of the shock
body.

STEP A-17

Screw the shock cap onto the shock body and tighten it finger tight.
Exercise the shock. If it squeaks, remove the cap to work out any addi­tional air bubbles.

Upper spring retainer

Ride height spacer

STEP A-18

Slide the upper spring retainer over the shock body. Snap a 2mm ride
height spacer onto the shock body between the shock cap and the
upper spring retainer. The ride height spacers (spring pre-load spacers)
will snap onto the shock body from the side and do not have to be slid
on from the end.

STEP A-19

Lower spring retainer

Slide a spring over the shock and secure it with the nylon lower spring
retainer.

STEP A-20

Use needlenose pliers to snap a hollow ball connector into the short rod
end. Repeat steps A-1 through A-20 for the 3 remaining shocks.

10

BAG B Ball Differential

Right 
o

utput shaft

D

iff ring

B

all

B

earing

Ball
Bearing

Diff balls

Diff ring

D

iff shaft

Thrust washer
r

etainer

L

eft
output
shaft

T

hrust washer

Thrust
b

earing

B

elleville
spring
washers

Main diff pulley

This drawing is provided to help you identify the parts of the
ball differential by name.

STEP B-1

Locate the main diff pulley and pack each of the 10 holes with the sup­plied diff lube. Insert a 1/8” diff ball into each of the holes. Push the balls
into the side with the boss around each hole (larger opening). Use a
plastic pen cap to push the balls into the holes. Place a small dab of diff
lube on each ball, on both sides of the pulley.

STEP B-2

Press a 5x8mm ball bearing into the center of the diff gear.

STEP B-3

The metal parts of the ball differential are coated with a rust and corro­sion prohibitor. Use solvent to remove the protective coating before
assembly.

STEP B-4

Locate the diff shaft and the 4 belleville
spring washers. Note that one face of
each spring washer is dished. Place the
washers on the shaft in the sequence
shown in the drawing.

STEP B-5

Locate the grooved thrust washers and the thrust bearing. Smooth a thin
layer of thrust bearing grease into the grooves in the thrust washers.
Slide the thrust washers and thrust bearings over the shaft in the
sequence shown in the drawing.

11

Rounded
edge on
face

STEP B-6

Locate a 26mm diff ring. Note that one face of the
ring has a rounded edge. The opposite face is
sharp. Place the ring onto the face of the aluminum
thrust washer retainer so that the so that the side
with the rounded edge faces you. Align the notch
with the pin.

STEP B-7

Insert the threaded end of the diff shaft assembly through the center of
the flat side of the thrust washer retainer. The thrust washer should fit
perfectly into the recess in the thrust washer retainer (arrow).

STEP B-8

Locate the right output shaft, and the remaining 26mm diff ring. Again,
note that one face of the ring has a rounded edge. The opposite face is
sharp. Place the ring onto the face of the aluminum thrust washer retainer
so that the so that the side with the rounded edge faces you. Align the
notch with the pin.

5x8mm ball bearing

STEP B-9

Press a 5x8mm ball bearing into the center of the shaft.

STEP B-10

Insert the retainer/dif
pulley assembly until the diff ring contacts the diff balls.

f shaft assembly through either side of the main

12

right output shaft
assembly

Do not grip with pliers
on this surface!

Left output shaft
assembly

STEP B-11

Screw the right output shaft assembly from STEP B-8 onto the diff shaft
from the opposite side of the main pulley. Make sure that the belleville
washers are compressing, without binding. Tighten until the threads
stop. Back off 1/4 to 1/8 turn in order to get within range of the final
adjustment (made after the model is assembled). Do not tighten and
loosen the diff adjustment any more than necessary to prevent wearing
off the thread locking compound.

STEP B-12

Fasten the left output shaft to the thrust washer retainer using three
2x4mm cap screws with split lockwashers. Tighten them firmly but be
careful not to overtighten. Repeat steps B-1 to B-12 to build the second
ball differential.

right output shaft assembly

hollow-ball connectors

turnbuckles

STEP B-13

Ball Differential Adjustment: Check the assembled diff for smooth opera­tion. Now is a good time to study the mechanism so that you will under­stand how it adjusts after it is installed in the Car. Hold the left output
shaft and rotate the gear until you can see through the hole in the shaft.
Insert the 1.5mm allen wrench into the hole to lock the diff. Turn the
right output shaft to change the adjustment. When the diff is installed in
the model, you will turn the wheel connected to to the right output shaft
to change the adjustment. It takes only a very small turn of the wheel
(right output shaft) to change the adjustment.

BAG C

Assemble the Turnbuckles and Upper control Arms. The dimensions
specified will give rough alignment. Final alignment should be done with
camber and toe gauges.

STEP C-1

Locate the (4) 24mm titanium turnbuckles, (1) 36mm turnbuckle (6) short
rod ends, (4) long rod ends, and (10) metal hollow-ball connectors. Notice
that each turnbuckle has both left and right handed threads (see diagram).

STEP C-2

ie Rods (Quantity: 2) Use the short rod ends on 24mm turnbuck

T

Front
les for the tie rods. Assemble as shown.

-

short rod ends

13

38mm

STEP C-3

Snap in the metal hollow ball connectors with needle nose pliers.

STEP C-4

Rear Camber links (Quantity: 2) Use the long rod ends on 24mm turn­buckles for the rear rear camber links. Assemble as shown. Snap in the
metal hollow ball connectors. The center-to-center distance should be
38mm.

STEP C-5

Drag Link (Quantity: 1) Locate the 36mm turnbuckle and (2) short rod
ends for the drag link. Assemble as shown. Snap in the metal hollow ball
connectors. The center-to-center distance should be 50mm.

50mm

30.5mm

STEP C-6

Steering arm (Quantity: 1) Locate the 20mm threaded rod and (2) short
rod ends for the steering arm. Assemble as shown. Note that the rod
ends are turned 90-degrees from each other. Snap in the metal hollow
ball connectors. The center-to-center distance should be 30.5mm.

STEP C-7

Locate the upper control arms, (2) 26x4mm turnbuckles, the two upper
ball joints.

14

42mm

STEP C-8

Assemble the upper control arms as shown. The center-to-center dis­tance should be 42mm.

Set all of these assembled linkage components aside.

BAG D DRIVE SHAFT

STEP D-1

Drive shafts: In bag D, find the sub-bag containing the drive shaft com­ponents. From the “Tools” bag, find the U-joint assembly tool. Separate
the parts into like groups.

STEP D-2

Find (1) stub axle, (1) metal u-joint ball (spider), and one internal-splined
drive shaft (female).

STEP D-3

Begin assembly by inserting one pin of the metal U-joint ball into one
ear of the drive shaft joint.

STEP D-4

Use the u-joint assembly tool to snap the remaining pin into the opposite
ear. Apply pressure down while pushing so that both ears will spread
and reduce the possibility of stretching or breaking an ear. Wrap a rag
around the half shaft and the tool to help hold it.

U-joint assembly tool

15

STEP D-5

Insert another pin into one ear of the stub axle joint.

STEP D-6

Use the u-joint assembly tool to push the remaining pin into the stub
axle yoke. Again, apply pressure down while pushing so that both ears
will spread. Repeat steps D-1 to D-6 for the remaining 3 female drive
shafts and stub axles.

STEP D-7

Find (1) Differential output yoke, (1) metal u-joint ball (spider), and one
external-splined drive shaft (male).

STEP D-8

Assemble the (4) differential output yokes, male drive shafts, and metal
U-joint balls using the same procedure outlines in steps D-4 to D-6.

STEP D-9

All of the drive shafts need to be shortened to allow full suspension trav­el. Use a hobby knife to cut 2mm from the ends of the male and female
drive shafts.

16

STEP D-10

Insert (2) 3x3mm grub screws into each of the (4) differential output
yokes. Do not screw them in all the way. Set the drive shaft assemblies
aside.

BAG E: Sway Bars

E-1

Sway Bars: Locate the bag labeled “Sway Bars.” Find the (4) nylon
sway bar links. Locate (4) 3x5mm roundhead machine screws
(Hardware Bag).

E-2

Install a sway bar link onto each front suspension arm as shown. Note
the orientation and hole location
used. The recessed side of the
ball joint should face down. After
the car is assembled, you will be
able to adjust the action of the
sway bars by simply loosening
the screws and sliding the sway
bar link to the next position.

E-3

Attach the remaining sway bar
links to the rear suspension arms
with (2) 3x5mm roundhead
machine screws. Again, note the
orientation and hole location
used. Set the front and rear sway
bars aside for installation later.

BAG F FRONT DIFFERENTIAL HOUSING

F-1

Front differential housing: Locate the front differential housing and cover,
(2) 3x25mm buttonhead machine screws, and (2) 3mm flange nuts.

17

F-2

Insert a 3x25mm Buttonhead machine screw through the ears on the
front differential housing cover. Secure each screw with a 3mm flange
nut.

F-3

Locate one of the ball differentials and (2) 10x15x4mm ball bearings.
The bearings are in Hardware Bag.

F-4

Press a 10x15x4mm ball bearing onto each side of the ball differential.

Left

F-5

Find the 76-tooth drive belt. Wrap the 76-groove drive belt around the
differential pulley, and insert the Ball differential with bearings into the
front differential housing. Note the orientation of the ball differential. The
main drive pulley is offset to the left.

F-6

Fit the front differential housing cover onto the front differential housing
as shown.

18

F-7

Secure the cover to the housing in the front with (2) 3x8mm buttonhead
machine screws.

F-8

Secure the cover to the housing in the rear with (2) 3x6mm countersunk
self-tapping screws. Set this assembly aside.

F-9

Rear Shock Tower:

countersunk
holes to the
back.

Locate the rear shock tower, (2) 3x20mm buttonhead machine screws,
and (2) 3mm flange nuts.

F-10

Insert the 3x20mm screws through the lower holes in the shock tower
ear. Secure them with 3mm flange nuts. The lower countersunk holes
(visible in step F-9) should face the rear.

F-11

Use an M3x.05 tap to cut screw threads into the rear shock tower for the
body mount holes. Set the rear shock tower assembly aside. 3mm tap
and handle are not included.

19

F-12

Locate the graphite rear brace and the plastic bushing.

F-13

Use CA (cyanoacrylate) glue to glue the bushing into the graphite rear
brace. Note the orientation of the brace. The plastic bushing pushes into
the hole from the top. Set this assembly aside.

F-14

Rear Side Plates:

Belt tension
cam

Locate the right rear side plate, (1) belt tension cam, (1) 5x11x4mm ball
bearing, and (1) 10x15mm ball bearing.

F-15

Press the 5x11x4mm ball bearing into the pulley shaft hole in the right
side plate.

F-16

Press the 10x15x4mm ball bearing into the belt tension cam.

20

F-17

Insert the belt tension cam, with bearing, into the right side plate.
Position the notch in the belt tension cam in the forward-most slot
(arrow). This is the loosest setting. Set this assembly aside.

F-18

Right Stiffener and Brake Assembly:

Locate the right stiffener, the pulley shaft (two-speed shaft), (1) 5x8x.5
plastic washer
(2) metal brake pads, the graphite brake disk, (2) 3x15mm caphead
shoulder screws, the metal brake cam, and a 5mm E-clip.

, (1) 5x11x4mm ball bearing, the brake hub, (1) metal pin,

3x15mm caphead
shoulder screws

F-19

Press the 5x11x4mm ball bearing into the right stiffener. Slide a 5x8x.05
plastic washer over the end of the two-speed shaft.

F-20

Insert the two-speed shaft through the 5x11mm ball bearing in the stiff­ener. The plastic washer should be against the ball bearing (arrow).

Plastic washer

F-21

Insert the 2mm pin into the hole in the two-speed shaft. Slide the brake
hub onto the shaft (slotted end first) and engage the pin with the slot in
the hub. Push it on until it stops. When installed properly, the axle pin
will not be visible.

Slot

21

F-22

Slide the graphite brake disk onto the brake hub.

F-23

Snap a large E-clip into the groove in the top of the blue-anodized brake
cam.

F-24

Insert the end of the brake cam (opposite the E-clip) into the hole in the
bottom corner of the right stiffener. Twist the brake cam so that the flat
side, which is cut into the shaft, faces the graphite brake disk.

Flat side

F-25

Insert one of the metal brake pads between the brake cam and the
brake disk. The brake pad will fit into the flat cut into the brake cam
(shaft).

F-26

Slide one of the 3x15mm caphead shoulder screws through the top hole
in the remaining brake pad, and then through the top hole of the first
brake pad. Install the screw into the hole in the stiffener and tighten until
it stops.

3x15mm caphead
shoulder screws

22

F-27

Insert the remaining 3x15mm caphead shoulder screw through the bot­tom hole on each of the brake pads and then into the stiffener. Tighten
the screw until it stops.

F-28

7.5mm

Adjusting the Brake Pads: Screw the upper and lower brake pad screws
into the stiffener until there is only 7.5mm of exposed screw shoulder
between the pads.

F-29

Rear Side Plate Assembly:

Find the right rear side plate assembly from step F-17, a 5x8x2.5mm
plastic spacer, a 15-groove pulley and flange, an axle pin, and a large E­clip (5mm).

F-30

Insert the end of the two-speed shaft (right stiffener assembly) through
the 5x11mm ball bearing in the right rear side plate.

F-31

Slide the 5x8x2.5 plastic spacer onto the two-speed shaft. Insert an axle
pin into the hole in the two speed shaft.

23

F-32

Slide on the 15-groove pulley so that the slot in the pulley engages the
axle pin in the shaft. Slide on the pulley flange with the beveled side of
the flange facing the pulley (flat side faces out).

F-33

Secure the 15-groove pulley with a large (5mm) E-clip.

F-34

Locate the left side plate, 10x15 ball bearing, and belt tension cam.

F-35

Insert the bearing into the belt tension cam.

F-36

Insert the belt tension cam, with bearing, into the left side plate.

24

F-37

Locate the left side plate assembly, the 50-groove belt, the remaining
ball differential, and the graphite rear shock tower assembly.

F-38

Position the ball differential so that the differential pulley is offset toward
the right side plate. Place the belt around the differential pulley.

F-39

Fit the belt around the 15-groove pulley and then insert the differential
output shaft into the 10x15x4mm ball bearing in the right side plate.

F-40

Install the left side plate as shown by sliding the 10x15x4mm ball bear­ing onto the remaining ball differential output shaft.

F-41

Fasten the rear side plates together by installing the rear graphite shock
tower as shown, with (4) 3x10mm countersunk machine screws.

25

F-42

Locate the graphite rear brace. Install the rear brace, as shown, with (6)
3x8mm buttonhead machine screws.

F-43

Adjust the brake if necessary. Insert the 2.0 hex wrench under the rear
brace as shown. The rear mechanism should spin freely without drag­ging. If there is drag, loosen the brake adjusting screws slightly.

F-44

Rear Suspension:

Locate the left and right rear stub axle housings and (4) 5x11x4mm ball
bearings. Note that the stub axle housings are labeled “L” for left and
“R” for right. Press a ball bearing into the front and back of each stub
axle housing.

F-45

Locate the 38mm hinge pins, the 25.5mm hinge pins, (8) small E-clips,
and the rear camber links (38mm center-to-center distance). Also, find
the rear drive shaft assemblies from step D-9.

F-46

Snap a small E-clip into one groove of each of the four hinge pins.

26

F-47

Attach the lower rear suspension arms to the side frames by inserting
the 38mm hinge pins through the pivot point. Carefully notice how the
arms are positioned in the photo. Secure the opposite end of each hinge
pin with a small E-clip.

F-48

Attach the left stub axle housing to the end of the the left suspension
arm and the right stub axle housing to the right suspension arm by
inserting the 25.5mm hinge pins through the pivot points. Secure the
opposite end of each hinge pin with a small E-clip.

F-49

Locate the male drive shaft assemblies (with the differential output
yokes). Slide the differential output yokes onto the differential output
shafts. Note that the flats on the shaft must align with the flats molded
inside the differential output yokes.

F-50

Use a 1.5mm allen wrench to tighten the 3x3mm grub screws against
the differential output shafts. Do not overtighten these screws or you will
strip the plastic. Repeat for the other side.

F-51

Locate the female driveshaft assemblies (with the stub axles). Insert the
male half shaft into the female halfshaft assembly. Now, insert the metal
stub axle through the ball bearings in the stub axle housings. Repeat for
the other side.

27

38mm

F-52

Find the (2) rear camber links (38mm center-to-center), (2) 3x15mm
countersunk machine screws, and (2) 3x12mm countersunk machine
screws.

F-53

Attach the camber links to the upper inside holes in the ears of the side
plates with the 3x12mm countersunk machine screws.

F-54

Attach the outer ends of the camber links to the stub axle housings with
3x15mm countersunk machine screws.

F-55

Find the rear sway bar from step E-1. The rear sway bar is larger than
the front. Insert the ends of the sway bar through the holes in the sway
bar links (on the lower rear suspension arms). Note: the photo shows
the sway bar link in the wrong slot. Use the instructions from E-1.

F-56

Secure the rear sway bar with two 3x8mm buttonhead machine screws.

28

BAG G

Two Speed Assembly:

G-1

Locate the 45-tooth spur gear and the outer aluminum gear hub (with
the one-way bearing installed).

G-2

slide the 45-tooth spur gear onto the outer aluminum gear hub so that
the notches in the hub engage the tabs molded into the gear.

G-3

Secure the gear to the hub with the snap ring.
Use snap ring pliers.

ball bearing

inner gear hub

G-4

Locate the inner gear hub and and the 10x19x5mm ball bearing. Also
find a socket or some other round object which matches the diameter of
the outside race of the ball bearing (19mm diameter).

G-5

Use the socket and a mallet to gently tap the bearing into position.
socket should be sized to only touch the outside race of the bearing. If
you try to press from the inner race, the bearing will be permanently
damaged.

The

29

G-6

Locate the 41-tooth spur gear and another snap ring. Slide the spur
gear onto the hub so that the pins in the hub engage the holes in the
spur gear. Install the snap ring.

Two speed adjustment
screw.

Screw is flush
with edge of
counter bore.

Set screw for
the shaft.

G-7

Locate the drive hub. Set the adjustment set screw to be
flush with the counter bore as shown. Slide the drive hub
onto the two-speed shaft as shown. Note that the adjusting
screw is behind the set screw in the photo (arrow 2). Align
the set screw with the flat on the two-speed shaft and then
tighten the set screw.

2

G-8

Align the set screw with the flat on the two-speed shaft and then tighten
the set screw. Note: the adjustment is to the back.

G-9

Slide the two-speed gear and hub assembly onto the two-speed shaft.

G-10

Locate a 20-groove pulley
(5mm).

, pulley flange, (1) axle pin, and a large E-clip

30

G-11

Insert an axle pin into the hole in the two speed shaft.

G-12

Slide on the 20-groove pulley so that the slot in the pulley engages the
axle pin in the shaft. Slide on the pulley flange with the beveled side of
the flange facing the pulley.

G-13

Secure the 20-groove pulley with a large (5mm) E-clip.

BAG H

Upper Chassis and Bellcrank Assembly:

H-1

Locate the graphite upper chassis plate, battery plate, bearing block, (2)
3x6x8.9 bearing block spacers (blue anodized), (2) 3x6x10.75 bearing
block spacers (blue anodized), (2) 3x20mm buttonhead machine
screws, two 3x20mm countersunk machine screws, (4) 3mm locknuts,
and (2) 5x1

1mm ball bearings.

H-2

Insert the 5x1

1x4mm ball bearings into the bearing block.

31

H-3

Turn the bearing block over with the smooth edge facing you (arrow1)
The bearing block spacers have a slight taper (cone shape) on one end.
Insert the two 3x6x8.9mm blue spacers, tapered end first, into the bear­ing block as shown.

1

H-4

Position the battery plate as shown so that the countersunk holes align
with the spacers on the bearing block.

H-5

Insert a 3x20mm countersunk machine screw into each of the holes.

H-6

Turn the assembly over and secure the 3x20mm screws with (2) 3mm
locknuts. Compare your completed assembly with the photo to ensure
correct assembly.

H-7

ab

T

Locate the graphite top plate. Position (2) 3x6x10.75 bearing block
spacers (tapered end up) on the top plate as shown. Study the photo to
make sure that the topside of the top plate is facing you (note tab).

32

H-8

Place the bearing block assembly onto the top plate as shown.
Sandwich the assembly with your fingers and turn it over.

H-9

Insert two 3x20mm buttonhead machine screws through the remaining
bearing block holes.

H-10

Secure the 3x20mm screws with 3mm locknuts.

H-11

Steering Stops:

Locate (2) 3x6x1.5mm aluminum spacers, (2) 3x6x2.5mm aluminum
spacers, (2) 3x10mm buttonhead machine screws, and (2) 3mm nylon
locknuts.

H-12

Slide a 3x6x2.5mm spacer over each of the 3x10mm buttonhead
machine screws. Insert the screws through the holes in the graphite top
plate, as shown.

33

H-13

Slide a 3x6x1.5mm aluminum spacer over the end of each screw and
secure them with 3mm locknuts.

H-14

Locate the fuel tank and the rubber fuel tank isolators.

H-15

Install the main isolator (the wider one) around the main seam of the
tank.

H-16

Install the secondary isolator just above the main isolator.

H-17

Locate the graphite receiver plate, the antenna mount, and (1) 3x8mm
buttonhead machine screw.

34

H-18

Attach the antenna mount to the receiver plate with the 3x8mm button­head machine screw.

H-19

Locate the left stiffener (leftover from Bag F), (3) 3x6x8mm aluminum
spacers (blue anodized), (3) 3x20mm buttonhead machine screws, and
the fuel tank assembly.

H-20

Insert the 3x20mm buttonhead machine screws through the holes in the
receiver plate. Slide a 3x6x8mm aluminum spacer over each screw.

do not
tighten

H-21

The top isolator should fit uni­formly in the gap between the
tank and the top plate (see
photo at right).

Sandwich the fuel tank assembly (main rubber isolator)
between the left stif

fener and the graphite top plate.

H-22

Secure the top plate by fastening the radio tray to the left stiffener, as
shown, with the 3x20mm buttonhead screws. Slide the remaining
3x6x8mm aluminum spacer over the remaining 3x20mm buttonhead
machine screw and then insert the screw into the rear hole in the top
plate/stiffener assembly. Do not tighten this screw completely.

35

3x10mm

H-23

Locate the rear suspension/ right stiffener assembly from step G-12.
Fasten the top plate assembly to the right stiffener (3) 3x8mm and (1)
3x10mm buttonhead machine screws.

H-24

Locate the front pulley shaft, a 15-groove pulley and flange, a 20-groove
pulley and flange, (2) axle pins, (2) large E-clips (5mm), and the 121­groove (middle) belt.

H-25

Insert an axle pin through the hole in the
shaft. Slide the 15-tooth pulley onto the pul­ley shaft until the axle pin engages the slot
in the pulley. Slide the pulley flange onto the
shaft, with the beveled side facing the pul­ley. Secure the pulley with a large E-clip.

H-26

Insert the pulley shaft assembly through the bearing block as shown.
Insert an axle pin into the remaining hole in the pulley shaft.
Slide the 20-tooth pulley onto the pulley shaft until the axle pin engages
the slot in the pulley.

H-27

Wrap the 120-tooth drive belt around the rear 20-tooth pulley and then
over the front 20-tooth pulley.

36

H-28

Slide the pulley flange onto the shaft with the beveled edge facing the
pulley. Secure the pulley with a large E-clip.

BAG-I

Bellcrank Assembly

I-1

Bellcrank Assembly: Locate the left and right bellcranks and (4) 5x8mm
ball bearings.

I-2

Insert two 5x8mm ball bearings into each bellcrank

Boss

Left
bellcrank

I-3

Locate the (2) bellcrank posts, (2) bellcrank spacers, (1) 3x8mm and (1)
3x10mm buttonhead machine screw. The bellcrank posts and spacer
are blue anodized.

I-4

Insert the bellcrank posts through
the bellcranks. Study to photo closely
to insure that the bellcrank post
inserts through the bottom of the left
bellcrank (note that the boss on the
bellcrank arm points up).

37

I-5

Slide a bellcrank spacer over each bellcrank post.

I-6

3x10mm

3x8mm

Left
bellcrank

Boss

Attach the left bellcrank to the graphite top plate assembly with a
3x8mm buttonhead machine screw. Attach the right bellcrank post to the
top plate assembly with a 3x10mm buttonhead machine screw. The bell­crank spacer should be sandwiched between the top plate and the bell­crank. Study the photo closely to ensure that you have the left and right
bellcrank placement correct.

I-7

Front Suspension:

Locate the lower front suspension arms, the lower front suspension arm
mount, the graphite tie bar, (4) small e-clips, and the 45.5mm hinge
pins.

I-8

Snap a small E-clip into one groove of each of the hinge pins.

I-9

Attach the lower front suspension arms to the front suspension arm
mount by inserting 45.5mm hinge pins through the pivot points. Carefully
notice how the arms are positioned in the photo.
each arm should point up.

The sway bar link on

38

I-10

Slide the graphite tie bar over the hinge pins as shown. It may be nec­essary to use a 1/8” (.125) drill bit to open up the holes in the tie bar.
Secure the opposite end of each hinge pin with a small E-clip.

I-11

Locate the front sway bar.

I-12

Insert the ends of the sway bar through the links in the front suspension
arms.

I-13

Locate the front bumper. Use a sharp hobby knife to trim off the corner
as shown.

I-14

Locate the blue-anodized aluminum bottom chassis and (4) 3x20
countersunk machine screws.

39

I-15

Position the front bumper with the lower suspension arm mount as
shown. The tab on the bumper locks into the lower mount.

I-16

Position the front differential housing onto the lower suspension arm
mount. The tabs on the side of the differential housing should engage
the slots in the lower mount.

I-17

Attach the front suspension assembly,
bumper, and lower suspension assembly to
the chassis as shown with (4) 3x20mm
countersunk machine screws.

I-18

Locate your throttle servo (not included
with the kit). Install the throttle servo into
the right stiffener with the output shaft
positioned as shown. Secure the servo
with (4) 3x8mm buttonhead machine
screws. Route the servo
lead through the slot in the
bottom of the right stiffener,
under the fuel tank, and
then over to the receiver plate.

I-19

Position the upper chassis assembly
onto the lower chassis as shown.
Note that the front belt must be
placed around the pulley as the
upper chassis is positioned.

40

I-20

Turn the assembly over and fasten the lower chassis to the upper chas-

1

2

3

4

6

5

8

7

9

14

13

10

16

15

12

11

sis with (16) 3x10 countersunk machine screws in the locations indicat­ed in the photo.

I-21

Locate the drag link from step C-5 (50mm center-to-center), (2) 3x10mm
caphead machine screws, and (2) 3x6x.5mm flat metal washers.

50mm

I-22

Fit the drag link through the middle of the front belt and then position it
on the bellcranks as shown. The washers insert under the hollow ball
connector on each bellcrank

I-23

Fasten the drag link to the bellcranks with the 3x10mm caphead
machine screws and 3x6x.5mm flat metal washers. The washer inserts
between the hollow ball connector and the bellcrank (arrow).

I-24

Locate the upper control arm mount, (2) 33.5mm hinge pins, (4) small e­clips (3mm), (2) 3x12mm buttonhead machine screws, (2) 3x15mm but­tonhead machine screws,and the upper control arms (from step C-8).

41

I-25

Snap a small E-clip into one groove of each of the hinge pins.

I-26

Attach the upper front control arms to the upper control arm mount by
inserting 33.5mm hinge pins through the pivot points. Secure the oppo­site end of each hinge pin with a small E-clip.

3x12mm

3x15mm

I-27

Position the upper control arm assembly on the upper chassis as
shown. Note that the assembly must go through the middle of the front
belt. Fasten the assembly to the upper chassis with (2) 3x15mm button­head machine screws in the front and (2) 3x12mm buttonhead machine
screws in the rear.

I-28

Locate the thick and thin caster spacers. Insert (1) thick spacer in the
front location and (1) thin spacer in the rear location on each upper control
arm.

I-29

Locate the front left and right stub axle housings, (4) threaded metal
inserts, (4) 5x11x4mm ball bearings, and (4) 3x8mm caphead machine
screws.

42

I-30

Insert the threaded metal inserts
into the front axle housings. If
necessary, use a drop of CA glue
(Super Glue™) on each to pre­vent them from falling out during
assembly.

I-31

Insert the bearings into the front axle housing.

I-32

Locate the male front drive shaft assemblies (with the differential output
yokes). Slide the differential output yokes onto the differential output
shafts. Note that the flats on the shaft must align with the flats molded
inside the differential output yokes.

I-33

Use a 1.5mm allen wrench to tighten the 3x3mm grub screws against
the differential output shafts. Do not overtighten these screws or you will
strip the plastic. Repeat for the other side.

I-34

Locate the female driveshaft assemblies (with the stub axles). Insert the
male halfshaft into the female halfshaft assembly.

43

Bosses

3x8mm
caphead
screw

I-35

Insert the metal stub axle through the ball bearings in the front axle
housing. Note that the stub axle housings are labeled “L” and “R” for left
and right. Apply a drop of threadlocking compound to the threads of a
3x8mm caphead machine screw. Fasten the front axle housing to the
upper control arm with the 3x8mm caphead machine screw. Repeat for
the other side. Make sure the bosses are pointing up (arrow).

I-36

Turn the car over. Apply threadlocking compound to the threads of a
3x8mm caphead machine screw. Fasten the front axle housing to the
lower suspension arm with the 3x8mm caphead machine screw. Repeat
for the other side.

I-37

Locate the front tie rods (33.5mm center-to-center distance), (2)
3x12mm countersunk machine screws, (2) 3x15mm countersunk
machine screws, and (2) 3x6x2.5mm aluminum spacers.

spacer

I-38

Attach the tie rods to the front axle housings with the 3x15mm counter­sunk machine screws along with the3x6x2.5mm spacers. The spacer
inserts between the hollow ball connector and the front axle housing
(see inset)

I-39

Attach the tie rods to the to the end of the bellcranks with 3x12mm
countersunk machine screws.

44

I-40

Shock Installation: Locate the front and rear shocks, (4) nylon shock
mounting bushings with washers, (4) 3mm nylon locknuts, and (4)
3x15mm countersunk machine screws.

I-41

The shock mounting procedure is
the same for all four shocks. Begin
by sliding a nylon shock mounting
bushing over the long screws in
the front and rear shock towers.

I-42

Slide the top the shock over the bushing, followed by the nylon washer.

I-43

Secure the top of the shock with a 3mm nylon locknut. Do not overtight­en the locknut. Overtightening will cause the bushing to swell and bind
the shock.

I-44

Attach the bottom of each shock to the lower suspension arms with the
3x15mm countersunk machine screws.

45

I-45

By now, your Nitro 4-Tec Pro should look fairly complete. Now it’s time
to install the engine and radio gear.

BAG-J

Engine Mount
Radio system installation

J-1

left side frame

3x25mm

shoulder
screws

stiffener

3x20mm

Locate the engine mount, (1) 3x20mm countersunk machine screw, (1)
3x25mm countersunk machine screw

, and (4) 3x10mm shoulder screws.

J-2

Insert the engine mount between the left stiffener and the left side frame
as shown.

J-3

Fasten the engine mount to the chassis with a 3x20mm countersunk
machine screw in the front hole, (4) 3x10mm shoulder screws in the
slotted middle holes, and a 3x25mm countersunk machine screw in the
rear hole. Do not tighten these screws. The engine mount needs to be
loose for adjustment.

J-4

Clutch Assembly:

Locate the 19-tooth and 15-tooth clutch bell gears, the clutch bell, and
(2) 5x10mm ball bearings.

46

J-5

Place a drop of thread locking compound on the threads of the clutch
bell. Screw the 19-tooth gear onto the clutch bell followed by the 15­tooth clutch bell. Place a heavy rag around the 15-tooth gear and use
pliers to torque the gear to approximately 5 in-lbs.

J-6

Press the two 5x10mm ball bearings into the center of the clutch bell.
The bearing in the back of the clutch bell should press in easily. The
bearing in the front may require you to tap it in with a hammer. Use the
4-way wrench as the pusher. Make sure that end of the tool only touch­es the outside race of the ball bearing. If you push on the center race or
the seal area the bearing will be damaged.

Split Beveled cone

J-7

Locate your engine (not included with this kit). The engine must be a .12

- .15 CI, side exhaust, short-crankshaft engine. Some engines with wide
recoil starters may not fit because of the starter (O.S. and clones).
These engines will require a backplate and an electric starter box. Also
locate the split beveled cone, the flywheel, the clutch shoes, the clutch
spring, and the clutch adapter nut.

J-10

Slide the split beveled cone onto the end of the crankshaft.

J-11

Slide the flywheel onto the crankshaft so that the tapered side will press
over the split beveled cone.

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J-12

Secure the flywheel to the crankshaft with the clutch adapter nut. Hold
the flywheel with a pair of “Channel Lock™” pliers while torquing the
adapter nut.

J-13

Install the clutch shoes as shown.
Refer to the diagram to ensure that
the leading and trailing edges of
the clutch shoes are positioned
correctly.

J-14

Close the ends of the clutch spring. Wrap the clutch spring around the
clutch shoes.

J-15

Locate the clutchbell, a chrome 3x10mm caphead machine screw (with
metal washers attached) and a 5x8x.05 plastic washer. Slide the washer
over the end of the 3x10mm caphead machine screw.

J-16

Place the clutch bell over the clutch shoes and secure it with the chrome
3x10mm caphead machine screw and plastic washer

.

48

J-16

Install the engine into the chassis. The engine assem­bly is a tight fit. In order to install it, you will need the
move the brake disk towards the center of the car and
fit the engine flywheel on the opposite side of the disk
(between the right stiffener and the brake disk). Attach

the engine to the engine mount with
(4) chrome 3x10mm caphead machine
screws (with washers). The engine
mount should be loose to allow gear
adjustment.

J-17

Adjust the engine placement so that the gears are perfectly inline, the
gear faces are parallel, and the gear backlash is .003-.005 inches.
Set the gear backlash by running a thin strip of note paper through the
gear mesh. Slide the engine back so that clutch bell gears and spur
gears are meshed tightly with the paper.

J-18

Turn the car over and firmly tighten all six of the engine mount screws.
After the screws are tight, remove the paper and check the gear
alignment for binding or excessive looseness.

J-19

Locate the exhaust header, gasket, (2) 3x23mm caphead machine
screws, and (2) 3x5mm split lockwashers.

J-20

Remove the 3x20 button head screw and spacer

.

49

J-21

Insert the gasket between the header and the engine. Fasten the header
to the engine with the (2) 3x23mm caphead machine screws and
3x5mm split lockwashers.

J-22

Install the throttle return spring between the spacer and the 3x20mm
buttonhead machine screw (removed in step J-19).

J-23

Reinstall the 3x20mm buttonhead machine screw with the throttle return
screw.

K-1

J-24

Connect the remaining end of the spring to the bottom hole of the throt­tle arm.

Bag K:

Radio System Installation
The following steps outline a typical radio system installation in the Nitro
4-Tec Pro. Installations will vary depending on the type and brand of
radio system used.
Before beginning the installation, the servos must be centered. Connect
the radio system components according to your manufactures instruc­tions. Install fresh batteries. Turn on the transmitter and receiver. Set the
throttle and steering trims to their neutral positions. Now turn off the
receiver, followed by the transmitter. Be careful not to turn any of the
servo output shafts during installation.

K-1

Locate the servo saver
countersunk machine screw, and (1) 3mm locknut.

, the steering link (from step C-6), (1) 3x15mm

50

K-2

K-2

Attach one end of the steering link to the servo saver with the 3x15mm
countersunk machine screw and the 3mm nylon locknut.

K-3

Attach the remaining end of the link to the inside hole in the left bell­crank with a 3x12mm countersunk machine screw. Note: If your radio
system does not have steering end point adjustment, we recommend
that you attach the link to the outside hole on the bellcrank. This will pre­vent the steering servo from trying to push through the inboard steering
stops.

K-4

Locate the receiver battery/ switch harness which came with your radio
system (not included in the kit). Install batteries in the battery holder.
Stretch a rubber balloon over the battery holder to protect it from fuel
contamination.

K-5

Use the large zip strap to secure the battery to the graphite top plate.
Route the wires in front of the fuel tank and over to the receiver plate.

K-6

Mount the on/of

f switch in the receiver plate as shown.

51

K-7

Locate your steering servo, the steering servo mounts, (2) 3x10 mm
countersunk machine screws, and (4) 3x8mm buttonhead machine
screws.

K-8

Attach the steering servo to the steering servo mounts with the (4)
3x8mm buttonhead machine screws. Note that the servo output shaft is
on the right in the photo.

K-9

fit the steering servo between the upper
and lower chassis assemblys. Attach the
servo to the lower chassis with (2) 3x10
mm countersunk machine screws. The
front holes will accommodate two different
standard servo sizes.

K-10

Locate your receiver. With the battery switch off, connect the two servo
leads and the battery lead according to the manufacturer’s instructions.
Gather all of the wires (including the antenna wire) at one end of the
receiver.

K-11

Stretch a rubber balloon over the receiver to protect it from fuel contami­nation. Secure the receiver to the receiver tray with a zip tie. Neatly bun
dle the servo leads with small zip ties. the wiring should be clear of the
steering mechanism and the exhaust system. Note picture not shown
with balloon.

-

52

K-12

Insert the antenna wire through the plastic antenna tube.

K-13

Insert the plastic antenna tube into the antenna mount on the receiver
plate.

K-14

Fold the excess antenna wire over the top of the antenna tube and
secure it with the vinyl antenna tip.

K-15

Locate the servo saver adapters. The servo saver will fit standard
Traxxas and Futaba standard servos without an adapter. Sanwa and
Airtronics servos may require an adapter.

K-16

Install the servo saver with adapter (if necessary) onto the steering
servo in the 12:00 position (straight up). Secure the servo saver with the
screw included in your radio system.

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Long end

K-17

Turn on the radio system and test the steering setup. Notice that the
drag link’s 3x10 Caphead screws strike the inboard steering stops at full
steering throw. Adjust your radio’s end point adjustment to limit the
steering. The cap screws should firmly contact the steering stops, but
should not try to push through them. This is important to prevent excess
current draw and possible damage to the steering servo.

K-18

Locate the throttle/brake servo horn, (2) rod guides, and (2) 3mm lock­nuts. Note: the servo is compatible with Traxxas and Futaba standard
servos. If you are using another brand of servo, use one of the universal
servo horns included with your radio system.

K-19

Attach the rod guides to the outer holes in the servo horn with the 3mm
nylon locknuts. Note that the rod guide points up on the long end and
down on the short end of the servo horn.

Short end

K-20

Locate the throttle rod, the brake rod, (4) screw collars, (5) 3mm grub
screws, the short piece of fuel tubing, the brake cam, (1) 3x6mm flat
metal washer, and the spring.

K-21

Insert the 3mm grub screws into
the four screw collars

K-22

Assemble the throttle linkage as shown.

54

K-23

Insert the end of the throttle rod through the top hole on the carburetor
throttle arm. Attach the servo horn to the servo, as shown, with the
screw included in your radio system.

K-24

Locate the brake cam lever and a 3mm grub screw.

K-24

Insert the brake cam through the brake cam. Position it as shown and
secure it with a 3mm grub screw in the top of the brake cam.

K-25

Slide a 3x6mm flat metal washer over the end of the brake rod followed
by the 20mm piece of fuel tubing. Secure the assembly with a screw col­lar and 3mm grub screw.

K-26

Insert the brake wire through the brake cam and then through the rod
guide.

55

K-27

Fasten a screw collar to one end of the brake rod with a 3mm grub
screw.

K-28

Locate your tuned pipe (not included in kit), the pipe coupler, the exhaust
hanger wire, 3x10mm countersunk machine screw, and 3mm locknut.

K-29

Attach the pipe support to chassis. The end of the pipe wire has been
bent up to accomodate the pipe. The bend is visible in Step K-31.

K-30

Attach the the coupler
to the end of the pipe.
Fit the other end of the
coupler over the end of
the header.

K-31

Insert the end of the wire through the hole in the end of the pipe.
the grub screw in the end of the pipe against the wire (arrow).

ighten

T

56

foam insert

Bag L

Wheels and Tires

L-1

Locate (4) molded foam inserts, (4) tires, and (4) wheel rims. Wash the
tires in warm soapy water. Let them dry completely before continuing.

L-2

Install the inserts into the tires.

L-3

Stretch the tires over the rims. Note: the tires are directional. Place the
wheels around the car to make sure that the arrows in the tread design
on each tire point to the front of the car.

L-4

Glue the tires to the rims with thin CA glue. Pull back the tire and allow
the glue to run into the tire/rim bead.

L-5

Locate (4) axle pins, (4) aluminum hex hubs (blue anodized), and (4)
4mm flange nuts.

57

hex nut

L-6

Insert an axle pin into the hole in the stub axle.

L-7

Slide the wheel hex onto the stub axle so that the slot in the hex hub
engages the pin in the stub axle.

L-8

Install the wheel over the hex hub (noting the tread direction) and
secure it with a 4mm flange nut. Repeat steps L-6 through L-8 for the
remaining three tires.

Bag M

Body Mounts

M-1

Locate the front body posts, the rear body posts, (4) nylon clamps, (4)
3x12mm buttonhead machine screws, and (2) 3x10mm countersunk
machine screws.

M-2

Attach the body posts to the front bumper with the 3x10mm countersunk
machine screws.

58

M-3

Attach the rear body posts to the rear shock tower as shown. Do not
over-tighten the clamp screws into the shock tower.

M-4

Locate the foam bumper, two body washers, and two body clips.

M-5

Slide the foam bumper over the front body posts and secure it with the
body washers and clips.

M-6

Connect a section of fuel line between the front fitting in the tank and
the pressure fitting on the header. Connect the back fitting in the fuel
tank to the carburetor inlet.

M-7

Congratulations! Your Nitro 4-Tec Pro is assembled.Now, refer to the
alignment specifications in the front of this manual and fine tune all the
wheel settings. Then, follow your engine manufacture’s engine break-in
instructions to prepare your engine.

59