GPM Racing 20CRMNTI Steel Spur Gear 39T (M1.0) for Arrma 1/5 Kraton 8S (MAKX039TS)

High-Strength Spur Gears for ARRMA 1/5 Vehicles

This aftermarket spur gear set is designed as a direct-use replacement for ARRMA 1/5 platforms. The MAKX039TS items are manufactured from 20CrMnTi steel and are supplied in three tooth counts—39T, 43T and 47T—with a 1.0 Mod pitch. These steel parts are intended for applications where increased wear resistance and dimensional stability are required under load.

Fitment and selection: the spur gears are compatible with the ARRMA 1/5 Kraton and Outcast models listed in the compatibility section below. Choose the tooth count to tune final drive characteristics—lower counts boost acceleration, higher counts favour top speed. Confirm the 1.0 Mod pitch and tooth count match your pinion and gearbox prior to fitting.

Installation guidance: verify mesh with the motor pinion, inspect mating surfaces and bearings for wear, and set a consistent backlash. Apply appropriate gear grease to the tooth faces and avoid over-tightening fasteners that could distort the carrier or misalign the mesh. Run the gearbox by hand to confirm smooth rotation before final assembly.

Compatible Models

• ARRMA 1/5 Kraton 4X4 8S BLX Brushless Speed Monster Truck RTR-ARA110002(Original Spur Gear 47T/M1.0)
• ARRMA 1/5 Outcast 4WD 8S BLX Stunt Truck RTR-ARA5810 (Original Spur Gear 47T/M1.0)
• ARRMA 1/5 Kraton 8S EXB 4X4 Roller Brushless Speed Truck-ARA5208(Original Spur Gear 39T/M1.0 & 47T/M1.0)
• ARRMA 1/5 Kraton 4X4 8S BLX EXB Brushless Monster Truck RTR-ARA5808V2(Original Spur Gear 47T/M1.0)
• ARRMA 1/5 Outcast 8S EXB 4X4 Roller Brushless Stunt Truck-ARA5210(Original Spur Gear 39T/M1.0 & 47T/M1.0)
• ARRMA 1/5 Outcast 4X4 8S BLX EXB Brushless Stunt Truck RTR-ARA5810V2(Original Spur Gear 47T/M1.0)

Confirm tooth count and M1.0 pitch before fitting, and use proper mesh setup techniques to ensure dependable gearbox operation under demanding RC use.

Are these intended as direct replacements for ARRMA stock spurs?

They are presented as replacements for the ARRMA models listed when the original tooth count and 1.0 Mod pitch match; verify model codes and counts prior to ordering for a correct fit.

What does 20CrMnTi provide over softer materials?

As a carburising alloy, 20CrMnTi supports a hardened surface layer after heat treatment which improves wear resistance and resistance to surface fatigue compared with non-hardened materials, useful for high-stress RC drivetrains.

How should I choose tooth count for my setup?

Select based on desired drive characteristics: lower spur tooth counts produce stronger acceleration at the wheel, while higher counts increase theoretical top speed; consider motor, pinion and terrain when deciding.

Any final tips for safe installation?

Check pinion compatibility with M1.0 pitch, establish correct backlash, inspect bearings and carriers for play, apply appropriate grease, and manually rotate the gearbox to confirm smooth engagement before use. Write Product Review Please sign in your account before you can write any review. Sign In Close

Made to order: GPM Racing parts are shipped to us from GPM's factory, so please allow around 14 days for dispatch.