MAHLE MS-979A-20 Engine Crankshaft Main Bearing Set Undersize - 0.020

The MAHLE MS-979A-20 is a premium AL-Series main bearing set designed for Ford inline 6-cylinder engines, including the 240, 250, and 300 cubic inch engines produced from 1966 to 1993. This complete set includes 7 bearings, featuring a 3.5670-inch diameter flanged thrust bearing for proper crankshaft positioning.

Key Features:

• AL-Series aluminum construction with 100% lead-free aluminum silicon alloy
• 0.020 inch undersize crankshaft journal dimension for rebuilt or machined crankshafts
• Manufactured with 100% bored inside diameters for optimum surface characteristics and consistent precision
• Features 1/2 groove in upper bearing shell for improved oil distribution
• Engineered with 60% more silicon than competitive replacements for better journal conditioning
• Cast copper-lead construction increases fatigue strength by approximately 20% compared to sintered designs
• Designed specifically for use with cast iron crankshafts
• Meets or exceeds OE specifications for direct replacement

The softer, more conformable nature of the aluminum alloy provides excellent wear characteristics and interacts closely with journal surfaces for enhanced strength and seizure resistance. Ideal for OEM-style engine rebuilds and mild performance applications where reliability and longevity are priorities.