TRAXXAS TRX4 Portal housing upgrade brass heavy set - TRX4021X by GPM  [TRX4021X]

TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X
Price:
NZD$70.76
Brand:
GPM
Model:
TRX4021X
GTIN:
4894538283372
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alt="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X" title="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X"
alt="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X" title="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X"
alt="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X" title="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X"
alt="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X" title="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X"
alt="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X" title="TRAXXAS TRX4 TRAIL CRAWLER Brass Outer Portal Drive Housing (Front Or Rear)'heavy Edition'-18pc set - GPM TRX4021X"

Brass-weighted portal housings tuned for TRX4 crawling

This heavy brass outer portal drive housing is a purpose-built upgrade for the TRAXXAS TRX4 chassis. Fabricated from brass to add rotating mass, each unit contributes roughly 50 grams per wheel to enhance tyre contact and slow-speed control when crawling uneven ground.

The components are suitable for either front or rear portal assemblies and come as a matched set to maintain axle symmetry. The added mass helps wheels hold traction when a tyre becomes partially buried, enabling the vehicle to regain grip and resume a neutral stance more smoothly.

Fitting hardware is included, with 16 stainless steel flat head screws sized 2.5x8. Installation is intended to be a straightforward bolt-on swap of the stock outer portal housings, with no core driveline changes required; follow standard TRX4 portal maintenance procedures.

Specifications

  • Item: Brass outer portal drive housing (heavy edition)
  • Material: Brass
  • Model Number: TRX4021X
  • Compatibility: TRAXXAS TRX4
  • Quantity Included: 18 pcs set
  • Included Hardware: Stainless Steel Flat Head Screw 2.5x8 - 16 pcs
  • Weight Effect: Adds ~50 g per wheel
  • Position: Front or rear portal housings

For TRX4 enthusiasts wanting a no-fuss way to add rotating mass and improve low-speed crawl performance, this brass outer portal housing set offers a direct-fit upgrade that prioritises stability and tyre bite.

This item is compatible with

  • TRAXXAS TRX4 Defender Trail Crawler

Are these compatible with aftermarket portal kits?

They are intended for TRAXXAS TRX4 portal housings; compatibility with third-party portal kits depends on bolt pattern and internal clearance, so verify before fitting.

What is the per-wheel weight increase?

Each brass outer housing adds about 50 grams of rotating weight at the wheel, which helps momentum when negotiating obstacles.

Is any machining or trimming required?

No cutting to the driveline is expected. These housings are designed for bolt-on replacement; follow normal portal removal and refit steps for the TRX4.

Should I change gear ratios after fitting heavier housings?

Most users do not need to change gearing for trail driving, but if you run extended hard climbs or notice higher motor temps, consider gearing or motor cooling adjustments.

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