The ARA311017 is Arrma's 42 tooth main diff gear in GP5 profile, for the 1/7 Felony, Infraction and Limitless.

The main diff gear takes drive from the input gear and passes it into the centre differential. Running against the 15 tooth GP5 input gear (ARA311016), it gives a 2.8:1 reduction. Every bit of power the vehicle makes passes through this mesh, and on the 1/7 platforms that is a considerable amount — a gear that has rounded off or lost teeth will grind and slip under load, usually noticed first as a chattering noise on acceleration.

GP5 means gear profile 5. The diff gear and the input gear must share a profile to mesh correctly. This gear pairs with the GP5 main input gear, part ARA311016 (15T). Arrma also produces gears in GP6 profile, which is a different tooth form — a GP5 diff gear will not run correctly against a GP6 input gear, no matter how the mesh is set. Check which profile your transmission uses before ordering.

Gears in a mesh wear together, so if the diff gear is damaged it is worth inspecting the input gear at the same time. Replacing both together is often the better repair, and it guarantees the profiles match.

Features

• 42 tooth main diff gear
• GP5 gear profile
• 2.8:1 reduction with the 15T GP5 input gear
• Genuine Arrma spare part

Fits

• Arrma 1/7 Felony 6S AVC 4X4 RTR Brushless All-Road Street Bash (ARA7617V2)
• Arrma 1/7 Infraction 6S AVC 4X4 RTR Brushless All-Road Street Bash (ARA7615V2)
• Arrma 1/7 Limitless 6S 4X4 Roller Brushless Street Speed, Clear (ARA7116V2)

Per Arrma's compatibility listing.

Needed to Complete

• Matching GP5 main input gear (ARA311016, 15T) if the input gear is also worn

Includes

1 x Main Diff Gear, 42T GP5 (ARA311017 / ARA-311017)