Overview The SKF BR3984 tapered roller bearing cone is built for heavy-duty differential service in trucks and commercial vehicles. With a 66.675 mm (2.625 in) bore and 112.712 mm outside diameter, it is manufactured from heat-treated high carbon steel for strength and fatigue resistance under sustained axle loads. SKF’s logarithmic roller–raceway profile and ultra-smooth surface finish promote even load distribution for smooth, quiet operation. Precision tolerances support consistent fit and setup in axle assemblies where preload and alignment are critical.

Application & Fit Engineered for front or rear axle differentials, the BR3984 cone handles combined radial and thrust loads typical of ring-and-pinion support. It is used across a wide range of North American and import truck applications spanning multiple decades, including Chevrolet, Dodge/Ram, Ford, GMC, International, Isuzu, and more. Identified in VMRS as 18001019 (differential bearing cone), this cone mates with cup 3920 (sold separately) and is referenced in SKF documentation as PER.3984/20. Interchangeable with common industry numbers (e.g., Timken 3984), it offers a drop-in, OE-dimension replacement to help standardize parts in mixed-age fleets.