Mugen MRX5 1st Gear 15T 7075 Hard Aluminum - Arrowmax AM-MRX5-A0001  [AM-MRX5-A0001]

Arrowmax 7075 first-stage gear for MRX5 tuning

This 1st gear is made for Mugen MRX5 vehicles and is produced by Arrowmax as part number AM-MRX5-A0001. It is CNC-machined from 7075-grade aluminum with a hardened finish and supplied as a direct-replacement for the gearbox first stage when wear or damage is present.

Swap it in when you find play or rounded teeth in the drivetrain; fitting a fresh 1st gear restores accurate tooth engagement and helps maintain smooth torque transfer through the transmission. The unit is a single-piece gear intended to mate with the standard MRX5 gearbox layout and common spur/pinion setups used on that chassis.

When fitting, verify gear mesh and backlash against the motor pinion and spur, ensure bearings are fully seated, and confirm free rotation before final assembly. Do not overtighten grub screws or clamp fittings to avoid deforming the gear seat. Light lubricant on the gear face during initial running will reduce break-in wear.