Federal Mogul FP523M20 Engine Crankshaft Main Bearing Set Undersize - 020

The Federal Mogul FP523M20 is a complete crankshaft main bearing set manufactured to .020" undersize specifications, designed for use during engine rebuilds where the crankshaft main journals have been reground. Federal Mogul — operating under the Sealed Power brand — is a globally recognized leader in precision engine bearing manufacturing, supplying both OEM and aftermarket applications.

Main bearings, also called crankshaft main bearings or crank bearings, support the crankshaft within the engine block and are critical to maintaining proper oil film pressure and long-term engine durability. The .020" undersize designation (M20) indicates these bearings are engineered to fit crankshaft journals that have been machined .020" below the original standard diameter.

Key Features:

• .020" Undersize — engineered for reground crankshaft main journals
• Manufactured to precise OEM dimensional tolerances for consistent oil clearance
• High-strength steel backing provides structural rigidity and reliable housing fit
• Bearing overlay material engineered for wear resistance, corrosion resistance, and fatigue strength
• Complete set includes all main bearing halves required for the application
• Meets or exceeds original equipment specifications for proper crankshaft support and lubrication

The Federal Mogul FP523M20 main bearing set is an essential component for any engine overhaul or crankshaft rebuild requiring an undersize replacement. Always verify crankshaft journal measurements prior to selecting bearing size to ensure correct oil clearance.