ARRMA MINI KRATON 3S 20CrMnTi Steel + 7075-T6 Alloy Rear Differential 12/30T 0.8 mod by GPM MAKM1230RS  [MAKM1230RS]

Rear differential upgrade for Mini Kraton 3S

This GPM rear differential assembly is a direct-scale replacement designed for ARRMA 1/16 Mini Kraton 3S platforms. The assembly combines heat-treated 20CrMnTi steel gearing with 7075-T6 aluminum housing components to improve load resistance and long-term wear life in high-torque brushless applications. Spiral-cut ring gear geometry and hardened surface treatment reduce noise and promote smoother torque transfer through the 12T input and 30T large bevel gears at 0.8 module.

The module and tooth counts match driveshafts that use 2 mm pins, and the unit is supplied fully assembled with internal bearings fitted. Note that differential fluid is not included, so you must add the correct silicone oil for tuning: the manufacturer recommends about 50K cSt for front diffs, 30K cSt for rear diffs, and 500K–1000K cSt for center diffs when applicable. Fasteners are pre-installed but using a medium-strength thread locker on critical screws is advised to prevent loosening under vibration.

Use this assembled rear differential when you need a durable, drop-in replacement for ARRMA Mini Kraton 3S rear drivetrains, especially in higher-load brushless setups where hardened steel and 7075 alloy components offer better longevity than stock plastic or softer metal parts.