This tough steel 18T MOD0.5 Pinion Gear provides a direct replacement for your kit item.
Features
- Strong and durable steel for long-lasting performance in extreme RC conditions
- Precision manufactured tooth profile for smooth operation
- Precision manufactured set screw hole
- For 2.3mm motor shaft
Includes
1 x 18T Mod 0.5 Pinion Gear
1 x M3 x 4mm Set Screw
- Brand: ARRMA
- Model Number: Z-ARA311204
- Product Type: Pinion Gear
- Number of Teeth: 18T
- Gear Pitch: MOD 0.5
- Material: Steel (hardened)
- Manufacturing Process: CNC precision manufactured
- Motor Shaft Bore: 2.3mm
- Set Screw Size: M3 x 4mm
- Set Screw Included: Yes
- Compatible ARRMA Models: 1/18 Granite Grom MEGA 380 Brushed 4x4 (all colour variants), 1/18 Mojave Grom MEGA 380 Brushed 4x4, 1/16 Mojave Grom 4x4 Race Kit, 1/14 Typhon Grom MEGA 380 Brushed 4x4 Buggy (all colour variants)
- Motor Compatibility: ARRMA MEGA 380 brushed motors with 2.3mm shaft
- EAN: 5052127047494
Overview
The ARRMA Pinion Gear 18T 0.5Mod CNC 2.3mm Bore is a precision-engineered replacement part designed for RC enthusiasts who demand reliability and performance from their electric RC models. Whether you're running a dedicated track car, a weekend basher, or competing in serious RC racing, having quality replacement gears on hand is essential to keeping your RC vehicle in peak condition. This tough steel pinion gear is specifically engineered to work seamlessly with ARRMA's popular 1/18 and 1/14 scale brushed motor systems, making it an ideal spare or upgrade component for owners of Granite Grom, Mojave Grom, and Typhon Grom models across the UK RC community.
Pinion gears are critical drivetrain components that directly impact your RC car's performance characteristics, acceleration response, and overall driving experience. When your original pinion gear becomes worn, damaged, or stripped from aggressive use, replacing it with a genuine ARRMA part ensures you maintain the exact performance specifications your vehicle was designed for. This 18-tooth variant offers a specific gear ratio that balances acceleration and top speed, making it suitable for mixed terrain and varied driving conditions. As an authorised RC retailer serving RC enthusiasts across the UK, RC Model Shop stocks genuine ARRMA components like this pinion gear to keep your fleet of RC cars running at their best.
The precision manufacturing process used to create this pinion gear ensures smooth mesh with the spur gear, reducing noise, vibration, and drivetrain wear. For anyone serious about maintaining their RC car UK collection, understanding the importance of quality replacement parts like this CNC-manufactured pinion gear is fundamental to enjoying years of reliable performance and consistent handling characteristics.
Key Features
- Tough Steel Construction — Manufactured from hardened steel, this pinion gear is engineered to withstand the extreme forces and stresses of aggressive RC driving conditions, whether you're bashing over rough terrain or competing on smooth indoor tracks. Steel gears maintain their tooth profiles far longer than plastic alternatives, ensuring consistent performance over extended use and multiple driving sessions.
- Precision CNC Manufactured Tooth Profile — Each tooth is machined to exacting tolerances using CNC (Computer Numerical Control) equipment, creating a perfectly uniform tooth profile that meshes smoothly with your spur gear. This precision manufacturing eliminates the slight imperfections found in injection-moulded plastic gears, resulting in quieter operation, reduced drivetrain backlash, and improved power transfer efficiency from motor to wheels.
- Precision Set Screw Hole — The mounting hole for the motor shaft set screw is manufactured with the same precision as the gear teeth themselves, ensuring that the gear sits perfectly centred on your motor shaft without wobble or run-out. A properly centred pinion gear meshes correctly with the spur gear, preventing uneven wear patterns and extending the lifespan of your entire drivetrain.
- 2.3mm Motor Shaft Compatibility — Specifically designed for ARRMA's MEGA 380 brushed motor systems with 2.3mm shaft diameter, this pinion gear fits directly into vehicles like the 1/18 Granite Grom, 1/18 Mojave Grom, and 1/14 Typhon Grom without requiring modification or adapters. This direct compatibility means installation is straightforward, and you're guaranteed proper fit and alignment every time.
- MOD 0.5 Gear Pitch — The MOD 0.5 (modulus 0.5) specification defines the tooth size and spacing of this pinion gear, ensuring it meshes perfectly with the corresponding MOD 0.5 spur gear fitted to your RC vehicle. Using the correct modulus rating is essential; mismatched gears will either not mesh properly or will cause premature wear and drivetrain damage.
- 18-Tooth Configuration — The 18-tooth count provides a balanced gear ratio suitable for general-purpose RC driving across various terrains and driving styles. This tooth count sits in the middle range, offering a good compromise between acceleration response and top-end speed potential, making it versatile for both casual bashers and competitive drivers.
Technical Performance
This ARRMA pinion gear represents the pinnacle of affordable precision engineering for RC models in the UK market. Built from hardened steel rather than plastic, it offers superior durability and consistent performance over thousands of hours of driving. The CNC manufacturing process ensures that every tooth is identical in profile and spacing, eliminating the micro-variations that occur in injection-moulded parts. This precision directly translates to smoother meshing with your spur gear, resulting in quieter drivetrain operation and more efficient power delivery from your MEGA 380 brushed motor to the wheels. The 2.3mm bore diameter fits perfectly on ARRMA's standard motor shaft, and the precision-machined set screw hole ensures the gear sits concentrically without any wobble. With a MOD 0.5 pitch specification and 18-tooth count, this gear is engineered to work exclusively with ARRMA's purpose-designed drivetrain components. The steel construction will outlast multiple plastic gear replacements, making it an economical choice for serious RC enthusiasts who run their vehicles frequently and demand reliability. Whether you're replacing a damaged gear or building a spare parts collection, this CNC-manufactured component represents genuine ARRMA engineering and quality standards.
What's in the Box
- 1 x 18T Mod 0.5 Pinion Gear (steel)
- 1 x M3 x 4mm Set Screw
Frequently Asked Questions
- What ARRMA vehicles is this 18T pinion gear compatible with? — This gear is designed for ARRMA 1/18 and 1/14 scale models equipped with MEGA 380 brushed motors featuring a 2.3mm shaft. Compatible models include the 1/18 Granite Grom (all colour variants), 1/18 Mojave Grom, 1/16 Mojave Grom Race Kit, and 1/14 Typhon Grom. Always verify your vehicle's motor specifications before ordering, as using the wrong pinion gear size will negatively impact performance and drivetrain longevity.
- Why should I choose a steel pinion gear over a plastic one? — Steel pinion gears are significantly more durable than plastic alternatives, resisting tooth wear and stripping even under extreme driving conditions. Whilst plastic gears are cheaper initially, they require more frequent replacement and don't maintain consistent mesh tolerances as they wear. Steel gears maintain their tooth profile precision throughout their lifespan, ensuring reliable performance and smoother drivetrain operation. For serious RC enthusiasts in the UK who drive regularly, a steel gear is a worthwhile investment that pays for itself through extended service life.
- What is MOD 0.5 and why does it matter? — MOD (modulus) is a measurement standard that defines the tooth size and pitch of a gear. MOD 0.5 gears have small, closely-spaced teeth designed for compact motor systems like ARRMA's MEGA 380. Using the correct MOD specification is critical; a MOD 0.5 pinion will not mesh properly with a MOD 0.6 or MOD 1.0 spur gear, resulting in drivetrain damage. Always match the MOD rating of your pinion and spur gears exactly.
- How do I know when to replace my pinion gear? — Replace your pinion gear if you notice skipping or slipping when accelerating, visible tooth damage or flattening, wobbling or run-out when the motor spins without load, or increased drivetrain noise and grinding sounds. Regular inspection during maintenance is recommended, particularly if you drive frequently or in abrasive conditions. Keep spare gears on hand so you can swap out a worn gear quickly and get back to driving without downtime.
- What is the difference between an 17T and 18T pinion gear? — The 17-tooth pinion provides slightly higher acceleration and lower top speed due to a lower gear ratio, whilst the 18-tooth gear offers slightly lower acceleration but higher top-end speed. The difference is subtle and depends on your driving style and track conditions. Experiment with both if you're racing competitively, or stick with the 18T for versatile general-purpose use.
- How do I install this pinion gear? — Remove the set screw from the motor shaft, slide the pinion gear onto the shaft until it seats properly, then re-install the M3 x 4mm set screw and tighten firmly. Ensure the gear is centred on the shaft and meshes evenly with the spur gear before tightening completely. Improper installation or a loose set screw will cause the gear to wobble, resulting in poor mesh and accelerated wear.
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 ARRMA Pinion Gear 18T 0.5Mod CNC 2.3mm Bore Z-ARA311204 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.
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