LOSA3578 Mod1 5mm Bore Pinion Gear (18T)

This product is a factory replacement hardened steel pinion gear designed for 1/8 and 1/10 scale Losi and Team Losi Racing vehicles that use a 5mm motor shaft. The LOSA3578 Mod 1 5mm Bore Pinion Gear (18T) is used to transfer power from the motor to the spur gear, playing a critical role in determining acceleration, top speed, and overall drivetrain efficiency. With its Mod 1 pitch and precision-machined construction, it is built to handle high-power brushless systems while maintaining smooth and consistent gear mesh. This is a direct OEM-style drivetrain component used for tuning or replacement.

Features:

• Genuine Losi replacement pinion gear
• Mod 1 gear pitch for high-power applications
• 5mm motor shaft bore
• 18-tooth gear configuration
• Hardened steel construction for durability
• Provides precise and efficient power transfer
• Helps tune acceleration and top speed characteristics
• Direct OEM replacement or upgrade part
• Designed for brushless and high-torque systems

Specifications:

• Part Number: LOSA3578
• Part Type: Pinion Gear
• Tooth Count: 18T
• Gear Pitch: Mod 1
• Bore Size: 5mm
• Material: Hardened Steel
• Application: Motor-to-drivetrain power transfer
• Installation: Set-screw mounted direct fit

What's Included:

• (1) Mod 1 18T 5mm bore pinion gear
• Set screw for installation

Community Feedback:

RC drivers commonly use Mod 1 pinion gears like this for tuning acceleration and top speed on high-power setups. Users report that proper pinion selection has a noticeable impact on heat management, efficiency, and overall performance. Many racers keep multiple pinion sizes available to adjust gearing for different track conditions or driving styles.