

Traxxas TRX4 - Build log, PART IV
Chassis time!
The frame for the chassis on the TRX4 is based on two beatuiful formed metal rails. They even got the Traxxas name milled in after being powder coated.
Here you can see the layout with the axles, rock-sliders, gearbox and joiners. Time to put it all together.
Inner fenders
To be able to use the Landrover body you have to change the innerfenders. On the landrover these are attached to the body whereas on the TRX kit they are a part of the chassis including the upper chock-mount. Part number 8018. Please be advised , the shocktowers are included in the long wheelbase extension kit. If you skip that kit you also need to buy the towers separately, part number 8216.
The option fender on the LEFT and the kit fender on the RIGHT.
Long wheelbase
The TRX4 can be build per quite a few different wheelbases. Check the manual for the body you are opting for if you need this kit. For the Landrover you need this 8057 kit.
The completed chassis
The chassis is finally built. No problems fitting the parts and the built actually feels like when I was young building those great Tamiya kits… Although the materials in the traxxas kit are way better than the plastic in the Tamiyas.
Option engine mount
Aluminum motor mount is a great option which I put on all of my builds. Traxxas has this part as an option and as I dont wan´t to disasemble the car after it is completed I opted to install it right away. The engine mount on the origila is made out of plastic.
The metalpart is slightly smaller then the notche in the gearbox so the motor can move up/down like 0.5mm. I reduced this by putting a piece of paper in between the plate and the cover when assembling.
Hobbywing Motor
The XERUN AXE 540L that came in the kit has a Kv of 2100 and will probably be a little to fast to be a crawler - but hey, my kids will love the speed :)
Motor fitted in the gearbox. THe gearmesh felt a bit tight but it was no problems neither with movement nor the sound of the gears.
Steering servo
For the steering I swapped the original servo for a Savöx SC1256TG which have some really good numbers. Be aware that Traxxas has a sligtly bigger CC between the mounting tabs so you have to modify all oter servos for them to fit properly. It is an easy modification though.
Aluminum steering arm is option for most models but standard in this one.
Next up will be the shocks!
Happy crawling!