ARRMA Mini Kraton 3S Center Differential 38T 0.8 Mod with Motor Plate & 15T Pinion by GPM MAKM1538S  [MAKM1538S]

Center differential for Mini Kraton 3S

This GPM complete center differential is a drop-in upgrade for ARRMA Mini Kraton 3S platforms, supplied fully assembled to replace factory part number ARA-2985. The assembly uses 20CrMnTi steel gears with a 7075 aluminum housing, and the internal geometry has been revised to use thicker gears for tighter meshing to reduce drivetrain power loss and improve transmission efficiency.

The unit is a 38T, module 0.8 center differential designed to work with standard 3.175mm motor shafts. GPM pairs the differential with a motor plate and a 15T motor pinion (0.8 mod) in this kit, and the differential accepts pinions in the 11T–23T range on that same 3.175mm bore. Note that the kit does not include differential oil, so viscous tuning must be added separately to suit handling and traction.

Installation notes: all supplied subcomponents arrive pre-assembled where applicable, and GPM recommends medium-strength threadlocker on critical fasteners to prevent loosening under use. The kit includes the motor plate and related hardware to replace the factory center assembly without major chassis modification.

Tuning guidance: because the center diff is delivered without oil, set viscous damping according to your handling goals and the vehicle position, for example the manufacturer suggests 50K CST for the front differential, 30K CST for the rear differential, and much higher values such as 500K CST or 1000K CST for the center differential depending on traction and steering response required.

This GPM center differential kit is appropriate for 1/16 ARRMA Mini Kraton 3S owners seeking a metal-gear, fully assembled center unit with a matched motor plate and 15T pinion, offering a straightforward replacement for ARA-2985 and expanded pinion compatibility.