Federal Mogul FP-3939859 Standard Connecting Rod Bearing Half - Cummins B-Series Diesel

The Federal Mogul FP-3939859 is a standard-size connecting rod bearing half engineered for Cummins B-Series diesel engines, including the 3.9L (4BT/4BTA) and 5.9L (6BT/6ISBE/ISB/QSB) engine families. Sold individually as an upper or lower half, this bearing is a direct OEM-specification replacement designed for engine rebuilds, overhauls, and in-frame service.

Key Features:

• Standard (STD) size — fits unmachined, factory-spec crankpin journals
• Direct replacement for Cummins OEM part number 3939859
• Engineered to OEM tolerances for proper oil clearance and load distribution
• Compatible with both upper and lower rod bearing positions
• Suitable for light-duty, medium-duty, agricultural, marine, and off-highway Cummins B-Series applications
• Cross-references: 3901170, 3901230, 3969562, 3971970, 3939800

The FP-3939859 is manufactured under the FP Diesel brand — Federal Mogul's dedicated aftermarket diesel engine parts line — and meets the demanding performance and durability standards required for Cummins B-Series engine service. This bearing half is commonly used as part of complete in-frame overhaul kits for the 4BT 3.9L and 6BT/ISB 5.9L and 6.7L engine series.