1989-2018 Cummins HX Series Race Main Bearings (PDM-MS-2328HXC)

Clevite HX-series coated main bearing set for 1989-2018 Dodge Ram and Ram 5.9L/6.7L Cummins engines. Developed for NASCAR-type race engines, equally well-suited to diesel builds making big power where cold-start protection and bearing survival matter.

The H-series base bearings have hardened steel backs with thin overlay, medium eccentricity, and high crush. Enlarged chamfers provide more clearance for crankshaft fillets. No flash plating — bearings seat faster and more uniformly. The HX series adds .001" of extra clearance over the H base, useful in builds where the main journal is on the edge of spec, or where extra oil film thickness is needed for sustained high RPM running.

The dry-film coating is the real advantage. It sits between the bearing surface and the crank journal, protecting the bearing during the brief window after startup when the oil pump hasn't pressurized the mains yet — and during any oil-starvation event. Moly and oil-retention additives in the coating hold film thickness under sustained load.

• Clevite HX-Series Coated Main Bearings — Complete Set
• Hardened Steel Back with Thin Overlay
• Enlarged Chamfers for Crank Fillet Clearance
• +.001" Clearance over H-Series Base
• Dry-Film Coating for Cold-Start Protection
• Moly & Oil-Retention Additives in Coating
• Fits 5.9L and 6.7L Cummins
• Part Number: PDM-MS-2328HXC

• Plastigauge journals before final assembly. The +.001" added clearance can push a loose journal out of spec.
• For the same coated bearings without the added clearance, see the H-series Performance Coated Main Bearings (PDM-MS-2328HC).