GPM Racing 20CRINTIH Steel + 7075 Alloy Front & Rear Complete Differential 30/9T for Arrma 1/5 Kraton 8S (MAKX0930S/2)

Front & rear complete differential for ARRMA 1/5

This GPM MAKX0930S/2 aftermarket assembly is a drop-in style front and rear differential set designed for ARRMA 1/5 8S platforms. Each differential is supplied fully assembled and uses mixed materials, combining 20CrInTiH hardened steel gears with 7075 aerospace-grade aluminium housings for a balance of strength and weight control appropriate to large-scale RC monster trucks.

The gear train uses helical 30T/9T gear pairs with a 2.0mm module, which improves mesh load distribution compared with straight-cut options while keeping backlash and noise predictable for tuning. The unit is sold without differential oil, so you must fill each diff with the silicone oil viscosity you prefer, the source recommends 100k cSt for maximum locking effect under heavy loads.

Compatibility and fitment follow ARRMA factory layout and this assembly replaces factory part number ARA310937. The set is intended for RC-scale applications only and is suitable for use where higher torque capacity and more robust gear engagement are required, such as aggressive off-road driving and stunt runs on ARRMA 1/5 platforms.

This product is supplied as a single set containing both front and rear assembled differentials in the 30/9T ratio, ready for installation after adding the chosen differential oil.

Compatible Models

• ARRMA 1/5 KRATON 4X4 8S BLX BRUSHLESS SPEED MONSTER TRUCK RTR-ARA110002
• ARRMA 1/5 OUTCAST 8S AVC 4X4 RTR BRUSHLESS STUNT TRUCK-ARA5810
• ARRMA 1/5 KRATON 8S EXB 4X4 ROLLER BRUSHLESS SPEED TRUCK-ARA5208
• ARRMA 1/5 KRATON 8S EXB AVC 4X4 RTR BRUSHLESS SPEED TRUCK-ARA5808V2
• ARRMA 1/5 OUTCAST 8S EXB 4X4 ROLLER BRUSHLESS STUNT TRUCK-ARA5210
• ARRMA 1/5 OUTCAST 8S EXB AVC 4X4 RTR BRUSHLESS STUNT TRUCK-ARA5810V2

Use this kit when upgrading ARRMA 1/5 trucks that demand higher gear strength and consistent diff behavior under heavy load, and verify diff oil choice to match your tuning goals before final installation.

Is this a direct replacement for the stock ARRMA ARA310937 differentials?

Yes, this GPM MAKX0930S/2 set is listed as a replacement for factory part number ARA310937 and follows the ARRMA 1/5 front and rear differential layout.

What differential oil should I use with these assembled diffs?

The product is shipped without diff oil, the source recommends 100k cSt silicone oil for a high locking effect, but choose viscosity based on traction and handling preferences.

What are the main materials and gear specs used in this kit?

The assembly uses 20CrInTiH hardened steel gears and 7075 aluminium housings, with helical 30T/9T gears at module 2.0mm specified for both front and rear.

Is the kit ready to install out of the box?

The differentials are fully assembled, but they require differential oil to be added prior to final installation and operation. 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.