4908 T-Maxx 3.3 Forward/Reverse Kit Instructions
www.TRAXXAS.com
Traxxas, 1100 Klein Road, Plano, TX 75074, Phone: 972-265-8000, Fax: 972-265-8011, e-mail: support@Traxxas.com
KC1154 Rev 080812
Covers Part #4995X
Important Note:
This kit does NOT include the OptiDrive system.
The truck must
come to a complete stop before shifting gears. See below for shifting instructions and
information about OptiDrive.
Transmission Removal
1. Remove the air filter from the
carburetor, and then remove the
throttle return spring from the
transmission case with a pair of
pliers (1A).
2. Loosen the set screw at the top of
the brake cam to release the brake
arm. Pull the arm from the brake cam (1B).
3. Flip the truck over and remove the four 3x8mm
countersunk screws that attach the center skid
plate to the chassis braces (1C).
4. Remove the screw pin from the rear transmission
output yoke, and then pull the
yoke off of the shaft leaving the
drive shaft assembly in tact (1D).
5. Next, remove the seven 3x15mm
cap head screws that secure the
transmission case to the chassis,
and then flip the truck back over
onto its wheels (1E).
6. Detach the throttle linkage
ball cup from the throttle arm
on the carburetor, and then
swing the throttle bell crank
around to where the long
throttle rod provides enough
space to pull the transmission
out of the chassis (1F). The
transmission should pull straight out of the chassis with the front drive shaft
half still attached.
7. Remove this drive shaft half by removing the setscrew pin from the output yoke (1G).
Forward / Reverse Gear Installation
1. Remove the seven 3x12
countersunk screws (2A) from the
transmission and separate the
transmission halves (2B).
2. Remove the forward-only gear
shaft assembly along with the
brake disc from the transmission (2C)
and then pull the blue rubber plug
from the front transmission half (2D).
3. Next, Place the steel primary
gear into the front
transmission half
followed by the disk
spring (see photo 2E for
correct orientation).
4. Slide the steel reverse
idler gear (with bearing)
over the molded plastic post next to the
steel primary gear (2F) followed by the
plastic idler shaft support (2G).
5. Locate the two black forward and reverse
gears along with the two metal needle
roller bearings. Press a roller bearing
assembly into each gear with the integral
marking facing out and away from the gears (2H). Be sure to press the bearing
assemblies all the way into each gear until it bottoms out inside the gear (2I).
6. Locate the forward/reverse output shaft, dog slider, four 6x8 Teflon washers,
and the two black forward/reverse gears with installed roller bearing
assemblies. Install these items onto the output shaft using the photo for correct
sequence and orientation.
Note
: The forward/reverse gears must be installed
onto the output shaft with the integral markings of the roller bearings facing
toward the center of the shaft (2J).
7. Next, locate the shift fork and shaft assembly. Position the
shift fork inside and around the groove of the plastic dog
slider on the output shaft (2K).
Note
: The shift fork shaft
must face toward the black reverse gear (thin gear).
8. Insert the entire assembly into the front transmission
half (2L). The output shaft is located through the 6x12mm
bearing at the bottom of the case, and the shift fork shaft
should slide through the same hole where the blue rubber
plug was removed (2M). Remember to position the front
brake disc between the brake calipers before sliding the
output shaft all the way into the transmission case.
9. Remove the forward-only primary gear from the
two-speed shaft by removing the primary pin retainer clip
from the gear to access the cross pin (2N). Push the pin
out of the gear and slide the gear off of the shaft.
10. Replace the gear with the included forward/reverse
primary gear in the same orientation and secure the gear
with the pin and retaining clip (2O).
11. Next, carefully join the two transmission halves together
and secure them with the seven
3x12mm countersunk screws (2P).
Reattach the front drive shaft
half to the output shaft of the
transmission and secure it with the
same screw pin (2Q).
12. Install the transmission back onto
the chassis in reverse order of how
it was removed. Remember to
rejoin the front drive shaft halves
together before securing the
transmission case to the chassis.
13. Reattach the throttle ball cup to
the carburetor, and then reconnect
the throttle return spring to the
transmission case. Secure the
brake arm back into the brake cam, and then reattach the air filter assembly
back onto the carburetor and secure it with the wire clip.
Channel 3 (CH3) / Shift Servo Installation
1. Locate the included #2060 shift servo and
adapter plate assembly and the four included
3x8mm button head screws (3A).
2. Loosen the two front screws that fasten the
steering servo to the servo mount about
halfway. Remove the 3x8mm button head
screw that secures the front steering servo
mount to the chassis (3B).
3. Slide the shift servo wire under the steering servo
mount between the chassis, and locate the wire into
the cutout molded into the mount (see 3C). After the
wire is safely contained inside of the cutout, secure
the servo mount back to the chassis with the removed
3x8mm button head screw, then tighten the front
steering servo screws.
4. Secure the shift servo and adapter assembly to the
servo mount next to the steering servo using the
included four 3x8mm button head screws. Note that
the adapter needs to be mounted so that the servo is in
an elevated position (see 3D for correct orientation).
5. Route the #2060 servo wire around the front of
the throttle servo mount toward the radio box.
Open the radio box, and then insert the shift
servo plug into the CH3-port of the receiver
(3E). Close the receiver box.
6. Locate the shift linkage wire
with the installed plastic ball
cup at one end. Insert the bare
bent end through the hole of
the shift fork shaft (from the
transmission)(3F), and then
connect the ball cup to the
pivot ball on the servo horn.
7. Turn on the transmitter and the model.
Press down on the red forward/reverse
switch (3G). The shift servo horn should
swing clockwise pushing the shift fork
shaft into the transmission (forward)(3H).
8. Press the red forward/reverse switch back
up (3I), and the servo horn should swing
counter clockwise pulling the shift fork
shaft out of the transmission (reverse)(3J).
Important:
If the shift servo horn swings in
the opposite direction than described above,
then switch the CH3 servo reverse switch on
the transmitter to the opposite position and
refer to
Centering the Shift Servo
.
Ensuring proper installation and engagement:
1.
Shift to reverse gear on the transmitter.
Roll the truck a few inches so that the shift
mechanism can fully engage.
2. Check the “pre-load” on the shift spring. You should feel a light resistance on
the servo horn.
Tools Needed
:
• 1.5mm hex wrench
• 2.0mm hex wrench
• 2.5mm hex wrench
• Needle nose pliers
• Small flat blade screwdriver
1A
2J
2K
2L
2M
2N
2P
2Q
2O
3B
3X8mm
Loosen
1B
1C
1D
1E
1F
2A
2B
2C 2D
2E
2F
2H
2G
2I
1G
3A
3D
3E
3F
3C
3G
3I
3H
3J
Front of Truck
080812_KC1154_4908_FwdRev.indd 1
8/12/08 5:01:40 PM
