GPM Racing Aluminium Lower Gear Cover - 13pcs Set for Traxxas 1/10 TRX4 (TRX4038BA)

Precision 6061 lower cover engineered for TRX-4

This CNC-machined 6061 aluminium lower gear cover is engineered for use on Traxxas TRX-4 chassis to shield the centre transmission and provide a rigid mounting surface under the frame. The hollowed profile is machined to reduce weight while maintaining structural stiffness and presenting exposed aluminium for passive heat transfer.

Installed, the cover reduces deformation in the transmission area and improves lower chassis rigidity, helping to stabilise suspension link mounts during technical, low-speed crawling. It is intended for scale hobby RC use only and not for any full-size application.

Hardware supplied matches the original lower cover fastener pattern for direct replacement on compatible TRX-4 variants, enabling accurate alignment with existing mounting points.

• Transmission Case Lower Cover – 1 pcs
• Stainless Steel Round Head Screw 3×25 – 2 pcs
• Stainless Steel Round Head Screw 3×16 – 4 pcs
• Stainless Steel Round Head Screw 3×10 – 4 pcs
• Stainless Steel Round Head Screw 3×8 – 2 pcs

Compatible Models

• Traxxas TRX-4 Defender
• TRX-4 Tactical Unit

Recommended for builds where transmission protection, improved chassis rigidity and passive thermal dissipation are required; supplied fasteners support precise, repeatable installation on the models listed.

What tolerances are relevant for fitment?

Confirm that the vehicle lower mount points align with the cover’s hole pattern. Minor tolerance differences can be accommodated by the supplied stainless fasteners, but check for correct seating during installation.

How does the hollow CNC profile affect stiffness?

The hollowed profile removes non-critical material to cut weight while preserving key load paths, resulting in a favourable stiffness to mass ratio for scale trail use.

Are the fasteners corrosion resistant?

The included stainless steel screws resist corrosion in typical hobby environments, helping maintain long-term fitment integrity and repeatable torque settings.

Any setup advice after fitting?

After installation, verify suspension link geometry and ride height. The additional lower stiffness can influence link dynamics, so fine-tune mounting positions if necessary for optimal handling. Write Product Review Please sign in your account before you can write any review. Sign In Close

Made to order: GPM Racing parts are shipped to us from GPM’s factory, so please allow around 14 days for dispatch.