INJORA +7mm Planet Axles with Double Joint Shafts for 1/18 TRX4M
INJORA +5mm Diamond Portal Axles for 1/18 TRX4M
INJORA +4mm Aluminum Axles for 1/18 TRX4M TRX4MT
INJORA +4mm Diamond Axles for 1/18 TRX4M
INJORA Overdrive Underdrive Alloy Steel Helical Gears for 1/18 TRX4M
INJORA Stub Axles Axle Shafts Gears for INJORA TRX4M Diamond Portal Axles
INJORA +4mm Planet Axles for 1/18 TRX4M
INJORA +4mm Aluminum Axles for 1/18 TRX4M
INJORA Axle Shafts Steeling Links for INJORA TRX4M +4mm Axles
INJORA +2mm Thread Axle Shafts for Stock Length TRX4M Axles
INJORA Aluminum Planet Axle Housings for 1/18 TRX4M +4mm Axles
FAQs about TRX4M Upgrade Parts
The most recommended first upgrades are:
- Servo – The plastic gears of the stock servo are fragile. Upgrade to a metal gear servo for stronger, more precise, and reliable steering.
- Metal Crawler Gears – Replace stock gears with metal ones to prevent wear and breakage under heavy use.
- Wheels & Tires – Upgraded wheels and tires provide better traction and grip, essential for crawling on rocks and loose surfaces.
- Shocks – Smooth out suspension for better control and stability on rough terrain.
- Brass Parts – Add weight in the right places (wheels, knuckles) to improve stability and lowers the center of gravity.
- Driveshafts & Links – Replace stock plastic driveshafts and links to prevent breakage and improve drivetrain durability.
The TRX4M is water-resistant.
Its electronics like the ESC, receiver, and servo are sealed, so It can handle wet surfaces, splashes, and light rainfall without issue.
However, it is not fully submersible. Avoid dunking it in deep water, and always clean and dry it afterward to prevent rust or damage to mechanical parts.
Upgrading to a brushless system is optional and depends on your goals and budget.
Our 180 brushed motor already provides a strong boost in torque and top speed at an affordable price.
Brushless systems usually perform better at low speeds and offer smoother control, but they require replacing the ESC and using a receiver with a CH2 port instead of the stock radio, which significantly increases costs. So brushless is mainly recommended for users with a larger budget or those seeking the best crawling performance.
Adding weight improves stability, traction, and climbing performance. The key is to add it low and toward the front to avoid tipping and excessive drivetrain strain.
Popular weight-adding spots include:
- Brass wheel weights, heavier wheels (most effective)
- Brass C hubs, steering knuckles, diff covers (optional)
- Brass skid plate, chassis links, steering links (optional)
Avoid adding too much weight high on the chassis—it can make the crawler tip over more easily and put extra strain on the drivetrain. Properly balanced weight helps your vehicle stay grounded and crawl more effectively over obstacles.
Here are some of the most common upgrades that can boost your crawler’s ground clearance and off-road performance:
- Larger tires – the most effective way to increase overall clearance. On the TRX-4M, tires over 64mm may cause body rubbing, so choose carefully, or you may need to trim or raise the body.
- High clearance links – lift the suspension links to prevent hang-ups and reduce the chance of them getting stuck on rocks or obstacles.
- Longer shocks and lift kits – provide more suspension travel and raise the body for extra clearance.
- High-clearance chassis – usually offers multiple mounting positions for optimal shock placement.
- Portal axles – if your rig supports them, they significantly increase ground clearance.
- Wheel hex extenders – widen the track to improve stability and reduce tipping.
These upgrades work together to help your vehicle navigate rough terrain more easily, improve approach and departure angles, and reduce chassis hang-ups.