Traxxas Half Shafts Centre External Splined Pin Retainers TRX8139

Overview

The Traxxas Half Shafts, Center (External Splined) (2)/ Pin Retainer (4) is an essential replacement drivetrain component designed for serious RC enthusiasts who demand reliability and performance from their scale crawlers and trail trucks. Whether you're running a Traxxas TRX-4, TRX-6, or compatible model, these centre half shafts are critical components that transfer power from your transmission to the wheels, ensuring smooth acceleration and precise control across demanding terrain. This is a genuine Traxxas OEM spare part, making it the perfect choice for anyone looking to maintain their RC car UK setup with authentic, manufacturer-approved components.

If you're a dedicated RC crawler pilot, a weekend basher, or someone who pushes their scale truck to its limits on rock gardens and technical trails, you'll understand the importance of quality drivetrain parts. The centre half shafts experience constant stress during operation, and having a reliable spare set on hand means you can keep your Traxxas RC vehicle running without extended downtime. These plastic parts are engineered to Traxxas' exacting standards, providing the durability and precision fit that separates genuine OEM parts from inferior aftermarket alternatives. Whether you need replacements after heavy use or you're building up a spares kit, the TRX8139 delivers peace of mind.

This pack includes everything you need to maintain or repair your Traxxas drivetrain: two centre half shafts with external splines and four pin retainers. The external spline design ensures a secure, reliable connection to your transmission while the pin retainers keep everything locked in place during operation. Compatible with a wide range of Traxxas models including the TRX-4 platform (from the classic 1972 Chevrolet Blazer to the modern Ford Bronco) and the six-wheel-drive TRX-6 Mercedes-Benz G 63 AMG, this is a versatile spare part that serious RC enthusiasts should always have in their toolbox.

Key Features

• Genuine Traxxas OEM Component — These are authentic manufacturer parts, ensuring perfect fitment and reliability compared to third-party alternatives. Using genuine Traxxas spares maintains your vehicle's warranty and guarantees quality standards.
• External Splined Design — The external spline geometry provides a secure mechanical connection to your transmission output, ensuring consistent power delivery without slippage or play. This design has been proven across thousands of RC crawlers and trail trucks worldwide.
• Includes Pin Retainers — The pack includes four pin retainers that secure the half shafts in place, preventing unwanted movement and ensuring the drivetrain operates as a unified system. These small but critical components protect your investment and maintain performance.
• Plastic Construction — Engineered plastic material balances durability with weight distribution, providing the right combination of strength and lightness for RC scale vehicles. This material choice has been perfected through years of Traxxas RC design and testing.
• Compatible with Multiple TRX-4 Variants — Works with numerous Traxxas TRX-4 models including High Trail Editions, Sport models, and standard configurations, as well as TRX-6 platforms. This broad compatibility makes it an excellent universal spare for Traxxas enthusiasts.
• Easy Maintenance Part — No special tools or expertise required for installation, making this an ideal spare for anyone who performs their own RC car maintenance and repairs. Clear design allows DIY installation with basic RC tools.
• Affordable Replacement Solution — These drivetrain spares are budget-friendly, allowing you to maintain a spares kit without breaking the bank. Keep multiple sets on hand for extended trail sessions without worrying about cost.

Technical Performance

The Traxxas TRX8139 half shafts represent the pinnacle of RC drivetrain engineering, specifically designed for the unique demands of scale crawlers and trail trucks that operate in extreme conditions. These centre half shafts are manufactured using high-quality engineering plastics that provide an optimal balance between durability and weight, crucial factors in RC vehicle performance. The external spline design is precisely machined to tolerances that ensure zero play when installed, eliminating drivetrain slop that would otherwise reduce steering responsiveness and power delivery efficiency. Each shaft is tested to handle the torque loads produced by Traxxas' powerful motors, whether you're running a brushless setup with multiple LiPo batteries or a more traditional brushed motor configuration. The inclusion of four pin retainers ensures that the half shafts remain securely seated during operation, preventing any lateral movement that could lead to premature wear or component failure. These parts have been engineered to work seamlessly with Traxxas' proprietary transmission designs, ensuring that installation is straightforward and the end result is a drivetrain that performs exactly as intended. Whether you're crawling over rocks, splashing through water crossings, or navigating technical obstacle courses, these half shafts will provide the reliability and performance you need to keep your Traxxas RC vehicle operating at peak efficiency. The plastic material also offers inherent cost advantages without sacrificing the structural integrity required for serious RC enthusiasts who demand their equipment to perform under pressure.

What's in the Box

• Half shafts, center (external splined) — 2x
• Pin retainer — 4x

Frequently Asked Questions

• Which Traxxas models are compatible with the TRX8139 half shafts? — The TRX8139 is compatible with a comprehensive range of Traxxas vehicles including the TRX-4 1972 Chevrolet Blazer High Trail Edition, TRX-4 1979 Chevrolet Blazer, TRX-4 1979 Ford Bronco, TRX-4 Chevrolet K10 High Trail Edition, TRX-4 equipped with Traxx, TRX-4 Ford Bronco, TRX-4 Ford F-150 High Trail Edition, TRX-4 Land Rover Defender, TRX-4 Sport High Trail Edition, TRX-4 Sport, TRX-4 Unassembled Kit, TRX-6 Mercedes-Benz G 63 AMG 6X6, and TRX-6 Ultimate RC Hauler. Check your specific model number against this compatibility list to ensure proper fitment.
• Why do I need to replace my half shafts? — Half shafts experience constant stress during RC operation, particularly when climbing obstacles, accelerating, or operating in extreme terrain. Over time, they can develop wear, stress fractures, or even break during intense use. Keeping replacement half shafts on hand ensures you can quickly restore your RC vehicle to operation without extended downtime.
• Do these come with everything I need to install them? — The TRX8139 includes the centre half shafts and pin retainers needed for installation. You'll use your existing drivetrain configuration and simply replace the worn or damaged half shafts. No additional parts are required for a standard installation.
• Are these genuine Traxxas parts? — Yes, the TRX8139 is an official Traxxas OEM component with the part number verified directly from the manufacturer. Choosing genuine parts ensures perfect fitment, proper performance, and maintains your vehicle's integrity.
• What makes plastic half shafts better than metal alternatives? — Traxxas engineers specifically chose plastic material for these half shafts because it provides the ideal balance of durability, weight, and cost-effectiveness. The plastic construction reduces overall vehicle weight while maintaining the strength needed to handle Traxxas motor torque output. Additionally, the material offers some inherent shock absorption that can protect other drivetrain components in the event of extreme impacts.
• Can I use these on any RC crawler or just Traxxas models? — These half shafts are specifically engineered for Traxxas vehicles and feature the exact spline geometry and dimensions required for proper fitment on Traxxas transmissions. They are not universal components and should only be used on compatible Traxxas models listed in the compatibility guide.

Why Buy from RC Model Shop?

RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the Traxxas Half shafts, center (external splined) (2)/ pin retainer (4) (plastic parts only) TRX8139 today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.