Overview
The Traxxas TRX-4M High/Low 2-Speed Transmission (TRX9891) represents a significant upgrade for enthusiasts looking to enhance their TRX-4M trail truck with superior rock-crawling capability. This fully assembled transmission unit brings a new level of versatility to your 1/18 scale RC crawler, allowing you to tackle both technical terrain and general driving with a single, intelligently designed system. Whether you're an experienced RC basher exploring challenging trails across the UK or a dedicated crawler seeking precision performance on rocky obstacles, this transmission delivers the torque and control you need.
What sets this transmission apart from standard fixed-ratio units is its innovative High/Low 2-speed design, which offers manually selectable gearing that adapts perfectly to different driving conditions. The system comes completely pre-assembled with a new Titan 180 motor and mounting bracket, meaning installation is straightforward and you can get crawling straight away. This isn't just an upgrade for performance enthusiasts—it's a complete solution that transforms how your TRX-4M responds to demanding terrain. For RC car enthusiasts in the UK seeking to maximise their trail truck's potential, this transmission delivers impressive results without requiring extensive technical knowledge or complicated installation procedures.
Traxxas has engineered this transmission to work seamlessly with your existing TRX-4M setup, maintaining compatibility with stock gearing and optional speed gear ratios. The manually selectable shifting lever puts you in complete control, letting you switch between low gear for technical rock-crawling sections and high gear for faster general driving—all without leaving the driver's seat. This flexibility makes the TRX9891 an essential upgrade for anyone serious about maximising their RC trail truck's capabilities.
Key Features
- High/Low 2-Speed Transmission — The transmission features two selectable gear ratios (32.7:1 low and 9.9:1 high), giving you incredible rock-crawling torque in low gear whilst maintaining standard high-speed capability for general driving. This dual-ratio design means you can tackle technical terrain and smooth trails with equal confidence.
- Fully Assembled with Titan 180 Motor — This transmission arrives completely assembled and includes a brand-new Titan 180 brushed motor, eliminating the need for additional motor purchases or complex assembly work. The motor is specifically tuned for optimal performance with this transmission system.
- Manual Shifting Lever — The integrated manual shifting lever allows you to select between low and high gears whilst driving, giving you complete control over your power delivery and enabling seamless transitions between different terrain types without stopping to make adjustments.
- Mounting Bracket Included — The transmission comes with a dedicated mounting bracket, ensuring proper fitment and alignment on your TRX-4M. This bracket is engineered for the TRX-4M platform and guarantees reliable installation.
- Compatible with Stock and Speed Gearing — This transmission works perfectly with standard TRX-4M gears and the optional 9776X speed gear set, allowing you to fine-tune your setup further. However, it is not compatible with 9776R crawl gears, so verify your current setup before purchase.
- Ready-to-Install Solution — The transmission arrives fully assembled and ready to install, making it an ideal upgrade for users who want improved performance without extensive technical work. Simply mount it on your TRX-4M and you're ready for enhanced crawling performance.
Technical Performance
The Traxxas TRX-4M High/Low 2-Speed Transmission represents sophisticated engineering designed specifically for 1/18 scale rock-crawling applications. The dual gear reduction ratios (32.7:1 in low and 9.9:1 in high) have been carefully calculated to provide maximum torque for technical climbing whilst preserving adequate speed for general trail driving. The included Titan 180 motor delivers consistent, reliable power across both gearing modes, with brushed motor technology providing proven durability and ease of maintenance that RC enthusiasts have trusted for years. The transmission case is engineered to withstand the stresses of rock-crawling, where extreme torque loads and technical manoeuvres demand precision-built components. The manually selectable gearing system uses a reliable mechanical shifting lever that requires no electronics or additional power sources, ensuring absolute dependability in the field. This transmission integrates seamlessly with the TRX-4M platform, respecting the vehicle's 1/18 scale proportions whilst delivering performance gains that are immediately noticeable during trail sessions. The complete assembly approach means all internal gearing, bearings and motor components have been matched and tested together at the factory, guaranteeing optimal performance from the moment you install it on your TRX-4M.
What's in the Box
- Complete 2-speed transmission assembly
- Titan 180 brushed motor (pre-installed)
- Mounting bracket for TRX-4M installation
- Manual shifting lever
Frequently Asked Questions
- What is the difference between the high and low gear ratios? — The low gear setting provides a 32.7:1 reduction ratio, delivering maximum torque for technical rock-crawling, steep climbs and obstacle courses where raw pulling power matters most. The high gear setting uses a 9.9:1 ratio, suitable for faster general driving and smoother terrain. You select between these ratios using the manual shifting lever whilst driving.
- Is this transmission suitable for beginners? — Yes, this transmission is excellent for beginners looking to upgrade their TRX-4M. It arrives fully assembled, ready to install, so you don't need to understand complex transmission internals. The manual shifting lever is intuitive to use, and the two gear ratios make it easy to adapt to different terrain without requiring advanced tuning knowledge.
- What battery does this transmission need? — The transmission itself doesn't have specific battery requirements as it's a mechanical system with no electronics. However, the included Titan 180 motor will work with standard LiPo or NiMH batteries compatible with your TRX-4M. Check your TRX-4M manual for compatible battery specifications.
- Is this compatible with my TRX-4M? — This transmission is designed specifically for the TRX-4M platform and is compatible with all TRX-4M variants including the Ford Bronco, Land Rover Defender, Chevrolet K10 and Ford F-150 models. It works with stock gearing and the optional 9776X speed gear set but is not compatible with 9776R crawl gears.
- Can I use this transmission if I already have a motor installed? — The transmission arrives with a Titan 180 motor already installed and ready to use. If you wish to use a different motor, you would need to remove the included motor and install your own, though this requires mechanical knowledge and may void any warranty considerations.
- How difficult is installation? — Installation is straightforward as the transmission arrives fully assembled with mounting bracket included. You simply attach the bracket to your TRX-4M chassis and secure the transmission unit. Basic mechanical aptitude and standard RC tools are all you need. If you're uncertain, RC Model Shop's experienced team can provide guidance.
- What makes this better than the standard TRX-4M transmission? — The standard TRX-4M transmission uses a single fixed gear ratio, whilst this high/low 2-speed system gives you two selectable ratios optimised for different terrain. This flexibility means you get superior rock-crawling torque when needed without sacrificing general driving capability, making it a versatile upgrade for various RC trail environments.
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 TRX-4M High/Low 2-Speed Transmission TRX9891 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.
- Model Number: TRX9891
- Product Type: Complete High/Low 2-Speed Transmission
- Manufacturer: Traxxas
- Compatible Vehicle: TRX-4M 1/18 scale trail truck
- Transmission Type: Manual shifting, 2-speed selectable
- Low Gear Ratio: 32.7:1
- High Gear Ratio: 9.9:1
- Included Motor: Titan 180 brushed motor
- Motor Type: Brushed DC motor
- Motor Size: 180
- Assembly Status: Fully assembled and ready to install
- Includes: Transmission assembly, Titan 180 motor, mounting bracket, manual shifting lever
- Gear Compatibility: Compatible with standard gears and optional 9776X speed gear set
- Not Compatible With: 9776R crawl gears
- Shifting Method: Manual lever selection (no electronics required)
- Installation: Comes with dedicated mounting bracket for TRX-4M
- EAN Code: 020334011855
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