Traxxas Close Ratio Gear Set (1st Speed 21T/18T Input) RC Gearset - 3973

The Traxxas 3973 is a close-ratio gear set for Traxxas transmission-equipped RC cars, providing a 21-tooth first speed gear and an 18-tooth input gear for tighter gear spacing across the rev range. Part number TRX3973, this gear set is designed as a direct-fit internal transmission component for compatible Traxxas models. Close-ratio gearing reduces the step between gear changes, keeping the motor closer to its power band and delivering smoother, more linear acceleration — particularly useful on technical tracks or surfaces where consistent drive matters more than outright top speed.

Key Features

• 21T first speed gear and 18T input gear deliver closer gear spacing than a standard wide-ratio set
• Close-ratio configuration keeps the drivetrain in a more efficient power range across gear changes
• Direct-fit Traxxas replacement part machined to OEM specification for the compatible transmission
• Suitable for restoring a worn transmission or reconfiguring gearing to suit specific driving conditions

Compatible With

• Compatible with Traxxas models using the matching multi-speed transmission that accepts TRX3973 internal gears — consult your model's manual or Traxxas parts diagram to confirm fitment before ordering

What's Included

• 21T first speed gear
• 18T input gear