This tough steel 38T Mod1 Safe-D5 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 5mm motor shaft diameter
- Precision manufactured threaded set-screw hole
- E-clip supplied for motor shaft pinion retention
Includes
1 x 38T Mod1 Safe-D5 Pinion Gear
1 x Set Screw - M4 x 4mm
1 x E-Clip - 3.2mm
Overview
The ARRMA Pinion Gear, 38T Mod1 Safe-D5 (Z-ARA311133) is an essential replacement component for RC car enthusiasts and serious bashers across the UK. This precision-engineered steel pinion gear is designed to deliver reliable performance in demanding RC racing and off-road conditions. Whether you're running a competitive RC buggy, a high-speed RC truggy, or pushing your RC truck to the limit on UK tracks, having quality replacement pinion gears in your toolbox is crucial for maintaining peak performance and minimising costly downtime.
Built from tough, durable steel and manufactured to exacting tolerances, this 38-tooth Mod1 pinion gear represents the kind of professional-grade component that separates serious RC hobbyists from casual operators. The Safe-D5 bore design is a standout feature that sets this gear apart from standard alternatives, offering significantly enhanced reliability and peace of mind during high-intensity driving sessions. For anyone operating brushless RC cars, electric RC trucks, or competition-level RC vehicles in the UK, this pinion gear is the perfect addition to your spares collection.
RC Model Shop stocks genuine ARRMA replacement parts because we understand that quality components directly impact your vehicle's performance, reliability and longevity. This 38T Mod1 Safe-D5 pinion gear is an OEM part that fits seamlessly into ARRMA RC vehicles and compatible models, ensuring you get the exact fit and performance characteristics your RC setup demands.
Key Features
- Safe-D5 Bore Design — The specially engineered D-shaped hole matches your motor shaft profile perfectly, ensuring that drive and braking power are never lost even if the set-screw backing out occurs, providing exceptional security and reliability during intense driving.
- Precision Manufactured Steel Construction — This pinion gear is machined from hardened steel using precision manufacturing techniques, delivering exceptional durability and long-lasting performance even in extreme RC conditions, harsh weather, and high-stress bashings.
- Wide Tooth Profile — The precision-manufactured wide tooth profile ensures smooth, efficient power delivery from motor to drivetrain, reducing vibration, minimising noise, and extending the lifespan of both the gear and your motor assembly.
- Mod1 Gear Pitch — The Mod1 (Module 1) pitch is a standard specification across ARRMA vehicles and many compatible RC cars, ensuring universal compatibility with your existing RC setup without requiring gear ratio recalculations.
- 5mm Motor Shaft Compatibility — Designed specifically for 5mm diameter motor shafts, this pinion gear suits a wide range of brushless and brushed RC motors commonly found in ARRMA and compatible electric RC vehicles.
- Threaded Set-Screw Hole — The precision-threaded M4 x 4mm set-screw hole accepts the included stainless steel set-screw, allowing you to secure the gear firmly to your motor shaft without risk of stripping or thread damage.
- E-Clip Retainer System — An E-clip (3.2mm) is included to provide additional shaft retention, preventing axial movement and ensuring the pinion gear stays precisely positioned during acceleration, braking and cornering.
Technical Performance
The ARRMA Pinion Gear 38T Mod1 Safe-D5 represents professional-grade engineering designed for high-performance RC applications across the UK. With 38 teeth and a Mod1 pitch specification, this gear delivers optimal speed and torque characteristics for competitive RC racing, weekend bashing, and everything in between. The precision-manufactured wide tooth profile ensures smooth mesh engagement with your spur gear, minimising backlash and maximising power transfer efficiency—critical factors when running high-KV brushless motors in 1/10 scale RC buggies, RC trucks, and RC truggy platforms. The Safe-D5 bore design is the real innovation here; the D-shaped hole conforms to your 5mm motor shaft, providing redundant drive security that prevents loss of power and braking control even if mechanical failure or vibration causes the set-screw to work loose during intense driving. This is particularly valuable in competitive environments where a single mechanical failure can cost you a race. The hardened steel construction withstands sustained high-load operation without permanent deformation, ensuring consistent mesh geometry and performance across thousands of operating cycles. Whether you're running a 2S, 3S, or 4S LiPo-powered RC car, or pushing a brushless RC vehicle at maximum throttle, this gear delivers the reliability and durability that separates quality replacements from budget alternatives.
What's in the Box
- 1 x ARRMA Pinion Gear, 38T Mod1 Safe-D5
- 1 x Set Screw - M4 x 4mm (stainless steel)
- 1 x E-Clip - 3.2mm (motor shaft retention)
Frequently Asked Questions
- What does the Safe-D5 bore design actually do and why is it better than standard round bores? — The Safe-D5 bore features a D-shaped hole that matches your motor shaft's profile. This dual-point contact design means that if your set-screw backs out due to vibration, the gear cannot slip on the shaft because the D-shaped bore grips the motor shaft mechanically. With a standard round bore, a loose set-screw means instant loss of drive and braking—potentially catastrophic during racing. The Safe-D5 design provides a critical safety net for reliability.
- Is this pinion gear suitable for beginners and casual bashers? — Yes, absolutely. Whilst this is professional-grade equipment appreciated by competitive racers, it's equally suitable for casual RC hobbyists, weekend bashers, and beginners who want reliable, quality components. The main difference is that serious racers will recognise the advanced engineering of the Safe-D5 bore and appreciate the redundancy it provides, but any RC enthusiast operating ARRMA vehicles will benefit from this gear's durability and smooth performance.
- Which ARRMA RC cars and RC trucks use this 38T Mod1 pinion gear? — This gear is compatible with any ARRMA vehicle (and compatible models) that feature a 5mm motor shaft and accept Mod1 pitch gears. Common applications include ARRMA electric RC buggies, RC trucks, RC truggies, and various scale bashers. Check your vehicle's manual or contact RC Model Shop to confirm compatibility with your specific model.
- How often should I replace my pinion gear? — With proper maintenance and set-screw checking, a quality steel pinion gear like this should last thousands of kilometres of RC driving. However, if you notice worn teeth, grinding noises, or visible damage, replacement is recommended. Many serious racers carry spare pinion gears (in multiple tooth counts) to adjust gear ratios for different tracks or conditions.
- Can I use a different tooth count to change my RC car's speed and acceleration? — Yes. This is a 38T gear. Lower tooth counts (e.g., 35T, 36T) increase top speed but reduce acceleration and torque. Higher tooth counts (e.g., 39T, 40T) increase acceleration and hill-climbing ability but reduce top speed. Many RC enthusiasts buy multiple pinion gears to tune their vehicle's performance characteristics for different driving conditions and tracks across the UK.
- What is the difference between Mod1 and other module pitches? — Module (Mod) refers to the pitch of the gear teeth. Mod1 is a standard pitch used across most ARRMA vehicles and many compatible RC cars. Using the wrong module pitch will cause poor mesh engagement and potential damage. Always match your pinion gear module to your spur gear module—check your vehicle's specifications.
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, 38T Mod1 Safe-D5 Z-ARA311133 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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