Almost done...Tamiya TXT

Dec 01, 2023

With the chassis side plates completed in part two, it's time to install the transmission and assemble the axles.

The transmission bolts into place with four screws, two per side, and aluminum supports brudge the side plates as well.

With both chassis plates installed and the transmission in place, we’re ready to move on to the axles.

First, the differentials. The aluminum diff cases house heavy-duty spider and output gears. The output gears are splined to accept steel half-shafts.

Before installing the diffs in the axles, a pair of bevel gears and an input gear are installed in the top hal;f of each axle. Unlike the Clod Buster, which mounts a motor on each axle, the TXT-2's motors are in the chassis, and power is transferred to the axles via shaft drive.

The diffs are installed in the top half of the axle. I photographed the parts dry, but I made sure to grease the gears thoroughly before buttoning up the axles. The instructions call for oilite bushings here, but Tamiya supplies ball bearings with the Agrios.

Axle halves assembled. Note the ball studs for the upper suspension links, the input shaft for the driveshaft, and the dogbone shaft ends.

Axle complete with steering knuckles and bumper/skidplate supports.

The driveshafts come next. The shafts come assembled as shown, and telescope at the end with the black collar to prevent drivetrain binding as the suspension moves through its travel range.

Aluminum suspension links snap onto the axles’ and chassis’ ballstuds to join the parts. To snap the large rod ends into place, I used a pair of slip-joint pliers and padded the jaws with a rag.

Note that the top links are triangulated, which prevents the axle from moving side to side but does not inhibit up/down and torsional travel. This configuration eliminates the need for a panhard bar or other axle-centering mechanism.

Oops, I got carried away and charged through the shock build without taking photos! The TXT-2 has eight shocks total, and Tamiya includes two large bottles of oil to fill them.

Chassis mostly complete–just need to install the electronics deck, battery tray, and body mounts.

The steering servo mounts behind the front skidplate/bumper. I installed a ProTek 330T servo, which is good for 254 oz. -in. of torque.

The wheels interface with an oversized hub that fits over a splined brass hex. &mm nuts secure the wheels. Wrestling the tires onto the wheels takes a bit of effort, and Tamiya says they should not be glued to the rims.

The electronics deck has diamond-plate detailing and is ready to accept cooling fans.

I installed a Tamiya TEU-106BK speed control to bring the TXT-2 to life. This controller is designed specifically for dual-motor monsters and has low-voltage detection for use with LiPo batteries.

Rolling chassis complete! All I have to do now is paint and mount the body. And then it should look like this:

…and here's video of the Agrios in action from Tamiya.com: