Overview

The Team Associated AS25844 12T 32DP hardened steel pinion gear is a precision-engineered drivetrain component designed specifically for 1/10-scale monster trucks, particularly the Rival MT10. This OEM-grade replacement gear is built to restore optimal performance and reliability in your RC car UK setup, whether you're a seasoned racer or weekend basher. Manufactured to exacting standards using hardened steel construction, this pinion gear delivers consistent power transfer from motor to spur, ensuring smooth acceleration and dependable torque delivery across all terrain types.

If you're running a brushless RC monster truck or need to fine-tune your gearing for better acceleration and throttle control, the AS25844 represents the trusted solution chosen by RC enthusiasts throughout the UK and beyond. Whether you're replacing a worn-out gear after extended use or upgrading your setup for competition, this pinion provides the precision and durability expected from Team Associated's reputation for excellence in RC component engineering.

The AS25844 is ideal for drivers looking to tailor their final drive ratio and achieve the perfect balance between acceleration and top speed. With its 12-tooth configuration and 32DP pitch, it integrates seamlessly with standard MT10 spur gears to help achieve smooth mesh and dependable performance in any ready to run RC setting.

Key Features

• 12-Tooth Configuration — The 12T tooth count is specifically engineered to balance torque and speed, making it perfect for versatile terrain handling whether you're bashing on grass, gravel, or hardpack surfaces. This tooth count delivers a 4.50:1 gear ratio when paired with the MT10's stock 54T spur gear, providing ideal performance for both acceleration and top speed control.
• 32DP Hardened Steel Construction — Built from precision-machined hardened steel, this pinion resists wear from high-RPM brushless motors and maintains its tooth profile even under extreme stress. The 32DP pitch specification ensures precise mesh with standard MT10 spur gears, eliminating backlash and providing consistent power delivery.
• OEM-Grade Fitment — This is the factory-spec replacement for the Rival MT10, engineered to restore drivetrain integrity after wear or damage. It's a direct replacement that maintains the original performance characteristics and reliability that Team Associated designed into the platform.
• 1/8-Inch Bore Diameter — The 1/8-inch (3.17mm) bore diameter matches standard Reedy 540-SL4 motor shafts used in the MT10 and compatible Pro4 SC10 RTR models. This ensures a secure fit that can handle the rotational stresses of modern brushless motors without slipping.
• Set Screw Compatible — The gear features a set screw mounting system that secures the pinion firmly to the motor shaft under stress. This design prevents gear slippage during aggressive driving or high-torque situations, maintaining consistent drivetrain engagement.
• Lightweight Design — At approximately 9.1 grams, this pinion minimises rotational mass, allowing your brushless motor to reach peak RPM more quickly and efficiently. Reduced rotational inertia translates to more responsive throttle control and better acceleration characteristics.
• Cross-Model Compatibility — Beyond the Rival MT10, this pinion is also compatible with select Pro4 SC10 RTR models. Both platforms share similar motor shaft diameters and spur gear configurations, making this a versatile choice if you run multiple vehicles.

Technical Performance

The Team Associated AS25844 represents precision engineering at the component level, machined to exacting tolerances that ensure reliable performance in demanding RC applications. The pinion features a pitch diameter of 0.375 inches (9.525mm) and an outside diameter of 0.4375 inches (11.1125mm), calculated specifically to provide proper engagement with 32DP spur gears used in the MT10 drivetrain. The root diameter of approximately 0.3027 inches (7.69mm) supports the full-depth gear profile, ensuring maximum strength and longevity under load. When properly meshed with the MT10's 54T spur gear, this 12T pinion delivers a 4.50:1 final drive ratio that has been proven to offer the perfect balance between acceleration response and top speed for both racing and recreational use. The hardened steel construction is essential for resisting the intense wear and stress generated by brushless motors, which can spin at extremely high RPMs. Unlike softer metals, the hardened steel in this pinion maintains its tooth profile over extended use, preventing the gradual degradation that leads to sloppy drivetrain response and eventual gear failure. The 32DP pitch specification is critical for integration with your existing MT10 spur gears, ensuring smooth, quiet operation without excessive backlash. Proper meshing not only optimises power transfer efficiency but also extends the lifespan of both pinion and spur gear by distributing loads evenly across the tooth surfaces. Installation is straightforward thanks to the standard 1/8-inch bore, which fits directly onto the motor shaft of the Reedy 540-SL4 brushless motors commonly used in the MT10 platform.

What's in the Box

• Team Associated AS25844 12T 32DP Hardened Steel Pinion Gear
• Set screw for motor shaft attachment

Frequently Asked Questions

• Is the Team Associated AS25844 12T pinion gear compatible with other RC models? — Yes, whilst the AS25844 is the factory-spec replacement for the Rival MT10, it is also compatible with select Pro4 SC10 RTR models. Both platforms use similar motor shaft diameters and spur gear configurations, making this pinion a reliable fit for either vehicle. However, compatibility with other brands or model series should be verified by checking bore diameter and spur gear pitch specifications.
• What makes hardened steel better than standard steel for RC pinion gears? — Hardened steel resists wear far more effectively than softer metals, which is critical when using brushless motors that spin at very high RPMs. Standard steel pinions gradually degrade during use, losing their precise tooth profile and developing backlash in the drivetrain. The hardened steel construction in the AS25844 maintains its integrity over extended use, preserving smooth, responsive gear engagement and preventing the sloppy drivetrain feel that comes with worn components.
• How do I know if I need to replace my pinion gear? — Signs that you need a replacement include visible damage to the teeth, grinding or unusual noises coming from the drivetrain, loss of responsiveness in acceleration, or visible tooth wear or chipping. If you've had your MT10 for an extended period of heavy use or have crashed hard enough to damage the drivetrain, the pinion gear may have sustained damage even if it's not immediately obvious. Replacing it with a fresh Team Associated OEM-spec component is an inexpensive way to restore your vehicle to factory performance.
• What gear ratio does the 12T pinion provide with the MT10? — The 12T pinion pairs with the MT10's stock 54T spur gear to deliver a 4.50:1 final drive ratio. This ratio has been engineered by Team Associated to provide excellent balance between acceleration and top speed, making it suitable for both racing and recreational bashing on varied terrain. If you want to adjust your gearing for different performance characteristics, changing the pinion tooth count will alter this ratio accordingly.
• Can I use this pinion with a different spur gear to change my gearing? — Yes, if you want to experiment with different gear ratios to fine-tune acceleration or top speed, you can pair the 12T pinion with spur gears of different tooth counts, as long as they are 32DP pitch to match this pinion. A lower tooth count spur gear will provide higher gearing (more speed, less acceleration), whilst a higher tooth count spur gear will provide lower gearing (more acceleration, less top speed). Ensure any spur gear you use is specifically designed for 32DP compatibility.
• Why is the 32DP pitch specification important? — The 32DP (32 pitch) specification refers to the number of teeth per inch of diameter and must match between pinion and spur gears for smooth, quiet, efficient operation. If you attempted to use a pinion of different pitch with your MT10 spur gear, you would experience poor mesh, excessive backlash, grinding noises, and rapid wear. The 32DP standard ensures that the AS25844 integrates perfectly with your existing MT10 drivetrain components.
• What is the bore diameter and why does it matter? — The AS25844 features a 1/8-inch (3.17mm) bore diameter, which is the hole through which the motor shaft passes. This matches the standard Reedy 540-SL4 brushless motors used in the MT10 and Pro4 SC10, ensuring a proper fit that can handle rotational stresses without slipping. Using a pinion with the wrong bore diameter could result in the gear spinning freely on the motor shaft, destroying drivetrain function entirely.
• How do I install the AS25844 pinion gear onto my motor? — The installation process is straightforward: slide the pinion onto your motor shaft so that the bore diameter fits snugly, then use the included set screw to lock the gear in place. The set screw should be tightened firmly enough to prevent any rotation of the gear relative to the shaft, but not so tight that you strip the threads. Ensure the pinion is positioned at the correct distance from the motor body to achieve proper mesh with your spur gear before fully tightening.
• Is this suitable for beginners? — Whilst the AS25844 is a component-level upgrade rather than a complete vehicle, it is suitable for anyone performing basic maintenance on their MT10. If you've been running your vehicle for a while and notice drivetrain wear, or if you've purchased a used MT10 and want to refresh the drivetrain components, replacing the pinion is a straightforward maintenance task. It requires only basic tools and mechanical knowledge.
• How often should I replace my pinion gear? — The frequency of replacement depends on your usage patterns. Casual weekend bashers might get months of service from a single pinion, whilst competitive racers running their vehicles multiple times per week may need to replace pinions more frequently. Inspect your pinion regularly for signs of wear, and replace it immediately if you notice tooth damage, chipping, or excessive wear. Using a worn pinion compromises performance and can accelerate wear on your spur gear as well.

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 Team Associated 12T 32DP Hardened Steel Pinion Gear for Rival MT10 – AS25844 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.