This tough steel 37T Mod1 Safe-D8 Pinion Gear is the perfect part to carry in your RC tool box
Features
- Strong and durable steel for long-lasting performance in extreme RC conditions
- Precision manufactured wide tooth profile for smooth operation
- 'D' shaped hole to match motor shaft profile so drive and brakes are not lost if the set-screw backs-out
- Suits 8mm motor shaft diameter
- Precision manufactured threaded set-screw hole
- E-clip supplied for motor shaft pinion retention
Includes
1 x 37T Mod1 Safe-D8 Pinion Gear
1 x Set Screw - M4 x 4mm
1 x E-Clip - 6mm
Overview
The ARRMA Pinion Gear, 37T Mod1 Safe-D8 is an essential replacement and upgrade component for RC enthusiasts running 8mm motor shafts on their electric RC vehicles. Whether you're a dedicated racer, weekend basher, or someone just getting into the world of RC car UK hobbies, having quality pinion gears in your toolkit is crucial for maintaining peak performance and reliability. This precision-engineered steel pinion gear delivers the durability and safety features you need to keep your RC machine running smoothly through intense driving sessions, whether on tarmac, dirt, or grass tracks.
ARRMA is recognised globally as a leading manufacturer of high-performance electric RC vehicles and components, and this 37-tooth pinion gear showcases their commitment to quality engineering and rider safety. The Safe-D8 design represents a significant advancement in pinion gear technology, specifically addressing one of the common failure points in RC drivetrains: the accidental loosening of the set-screw that secures the pinion to the motor shaft. Whether you're upgrading from a standard pinion gear or replacing a worn component, this gear represents a smart investment in your RC setup.
This tough steel pinion gear is the perfect part to carry in your RC tool box, offering the assurance that if your set-screw should back out during operation, your drive and brake systems remain fully engaged. For anyone serious about RC performance—whether running a ready to run RC vehicle or a custom-built machine—the ARRMA 37T Mod1 Safe-D8 pinion gear is an indispensable upgrade that combines protection, performance and reliability.
Key Features
- Strong and durable steel construction — The pinion gear is manufactured from high-quality steel that delivers long-lasting performance even in extreme RC conditions, ensuring your drivetrain can handle aggressive acceleration, hard cornering and extended driving sessions without premature wear or tooth stripping.
- Precision manufactured wide tooth profile — The wide tooth design ensures smooth operation and even load distribution across the gear mesh, reducing vibration, noise and wear on both the pinion and spur gear for extended component lifespan and superior driving experience.
- Safe-D8 'D' shaped bore — The distinctive 'D' shaped hole matches the motor shaft profile precisely, meaning that drive and brakes are not lost if the set-screw accidentally backs out during operation, providing critical safety and reliability that standard round-hole pinions cannot offer.
- 8mm motor shaft compatibility — Suits 8mm diameter motor shafts, making this gear compatible with a wide range of brushless and brushed motors commonly found in 1/10 scale and smaller RC vehicles across the UK RC community.
- Precision manufactured threaded set-screw hole — The set-screw hole is precisely threaded to accept the included M4 x 4mm set-screw, ensuring a secure fit that resists vibration-induced loosening and maintains consistent engagement with the motor shaft.
- E-clip supplied for motor shaft pinion retention — The inclusion of a 6mm E-clip provides an additional layer of retention security, working in tandem with the set-screw to ensure the pinion gear remains firmly fixed to the motor shaft under all driving conditions.
Technical Performance
The ARRMA 37T Mod1 Safe-D8 pinion gear represents the latest advancement in drivetrain safety and reliability for electric RC vehicles. Built from robust steel with precision manufacturing tolerances, this gear is engineered to withstand the extreme stresses encountered in high-performance RC applications. The Mod1 pitch (module 1) specification ensures compatibility with standard ARRMA and third-party spur gears, making this a versatile upgrade option for most brushless RC cars and trucks. The 37-tooth configuration strikes an optimal balance between acceleration and top speed, making it suitable for both on-road and off-road applications. The innovative Safe-D8 bore design addresses a critical failure mode found in conventional pinion gears: the catastrophic loss of drive and braking power if the set-screw loosens. By utilising the motor shaft's diameter profile as a mechanical key, the Safe-D8 design maintains engagement even if fastening hardware fails, a feature that has become industry-recognised as essential in competition-grade and high-reliability RC setups. The precision-manufactured wide tooth profile distributes load evenly across the gear mesh, reducing stress concentration points and extending the lifespan of both the pinion and spur gear. Whether you're running a high-speed brushless RC buggy, a crawling RC truck, or any electric RC vehicle in between, this pinion gear delivers the performance engineering you expect from ARRMA.
What's in the Box
- 1 x 37T Mod1 Safe-D8 Pinion Gear
- 1 x Set Screw M4 x 4mm
- 1 x E-Clip 6mm
Frequently Asked Questions
- What does the Safe-D8 design mean and why is it important for my RC car? — The Safe-D8 designation refers to the 'D' shaped bore hole that matches your 8mm motor shaft profile. This is critically important because it means that if your set-screw accidentally loosens during driving (which can happen with vibration), your pinion gear will not slip freely on the motor shaft. Instead, the 'D' shaped hole engages with the corresponding profile on your motor shaft, ensuring that drive and brake power are maintained. This is a significant safety feature that prevents sudden loss of control, making it especially valuable for competitive racing and high-performance driving on UK RC tracks.
- Is the ARRMA 37T Safe-D8 suitable for beginners? — Yes, this pinion gear is suitable for all experience levels. Beginners benefit from the Safe-D8 safety features which reduce the risk of unexpected drivetrain failures, whilst experienced racers and bashers appreciate the precision engineering and reliability. The inclusion of all necessary fastening hardware (set-screw and E-clip) means you have everything needed for installation, and the 37-tooth configuration provides a good all-around gear ratio for most driving styles.
- What motor types can this pinion gear work with? — The ARRMA 37T Mod1 Safe-D8 is compatible with any brushless or brushed RC motor that features an 8mm diameter motor shaft. This includes most standard 1/10 scale and smaller RC vehicles, covering the vast majority of hobbyist and competition-level electric RC cars and trucks available in the UK market.
- How do I install this pinion gear on my RC motor? — Installation is straightforward: slide the pinion gear onto your 8mm motor shaft, ensuring the 'D' shaped bore aligns with the shaft profile, then insert the M4 x 4mm set-screw through the threaded hole and tighten it securely. Finally, fit the 6mm E-clip onto the motor shaft to provide additional retention. Always ensure both the set-screw and E-clip are properly secured before operating your RC vehicle.
- What is the difference between this Safe-D8 pinion and a standard pinion gear? — Standard pinion gears feature a round bore hole, meaning they rely entirely on the set-screw's grip to remain fixed to the motor shaft. If the set-screw loosens, the pinion can slip, causing immediate loss of drive and braking. The Safe-D8 design uses a 'D' shaped bore that mechanically engages with the motor shaft, providing drive engagement even if fastening fails. This makes the Safe-D8 significantly safer and more reliable, particularly in demanding conditions where vibration and impacts are frequent.
- Why do I need the E-clip if I already have a set-screw? — The E-clip provides redundant retention by preventing the pinion gear from sliding off the motor shaft even if the set-screw were to completely back out. This dual-retention approach ensures maximum security and reliability, a particularly valuable safety feature in high-performance or competition RC driving.
- Is this pinion gear compatible with my ARRMA RC vehicle? — The ARRMA 37T Mod1 Safe-D8 is designed to work with ARRMA vehicles that feature 8mm motor shafts and accept Mod1 pitch pinion gears. We recommend checking your vehicle's specifications or consulting the ARRMA parts compatibility list to confirm compatibility with your specific model. Our team at RC Model Shop can also advise you on compatibility if you're unsure.
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, 37T Mod1 Safe-D8 Z-ARA311125 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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