2016-2019 BMW 7 Series Front Differential 31517647388

Also known as

Front Differential

Front Diff

Front Axle Carrier

Front Final Drive

Front Differential Assembly

xDrive Front Differential

Front Gearbox

What this part does

The front differential is a critical drivetrain component that receives rotational power from the transfer case and distributes it to the front wheels, allowing them to spin at different speeds when the vehicle navigates corners. On BMW xDrive models, this assembly is mounted tightly against the engine oil pan and connects the front driveshaft to the left and right CV axles. When the internal pinion gears, ring gear, or carrier bearings wear out, the unit typically produces a distinct howling, whining, or grinding noise that increases with vehicle speed. Severe internal failure can result in binding during tight turns, heavy vibrations felt through the floorpan, or catastrophic casing damage if the gears bind completely while in motion.

Fits these vehicles

OEM and interchange numbers

31517647388

31-51-7-647-388

7647388

Before you order

You must confirm your vehicle's required gear ratio before purchasing. This specific front differential has a 2.81 gear ratio. Installing a front differential with a ratio that does not perfectly match your rear differential will cause immediate and severe damage to your transfer case and transmission. Always verify the 11-digit part number stamped on your original housing. It is highly recommended to replace the left and right axle seals, as well as the pinion seal, while the unit is accessible on the bench. The unit is shipped drained of fluid; it must be filled with the correct specification of BMW gear oil prior to driving.