Sealed Power 4281M Engine Crankshaft Main Bearing Set

OE Replacement Main Bearing Set for Oldsmobile V8

Sealed Power 4281M is an OE replacement engine crankshaft main bearing set for Oldsmobile V8 applications with 350 and 403 displacement. Built with A-Series aluminum bearings, it is made for standard-size service and restoration work where correct crankshaft support and consistent bearing fit matter.

Compatible with a wide range of Oldsmobile, Buick, Cadillac, Chevrolet, and Pontiac vehicles, this Sealed Power 4281M main bearing set is a practical choice for rebuilds that need factory-style dimensions and dependable material selection.

• Engine crankshaft main bearing set for Oldsmobile V8 engines
• OE replacement application for standard rebuilds
• A-Series aluminum bearing construction
• Designed for 350 and 403 displacement Oldsmobile V8 engines
• Standard-size service options: Std-1-10-20-30-40
• Sealed Power engineering and ISO/QS certified manufacturing processes

Detailed Product Overview

The Sealed Power 4281M main bearing set is engineered for Oldsmobile V8 engines used in passenger cars and full-size applications across multiple GM nameplates. It supports crankshaft rotation by providing the bearing surface needed for proper oil film control and stable main journal support during engine operation. The A-Series aluminum bearing material is selected for rebuild applications where OE-style replacement dimensions are required.

This part cross-references Monroe Shocks & Struts (e.g., 1281K, MB5514MP) for the same application. Search terms such as Oldsmobile 350 main bearing set, Oldsmobile 403 crankshaft main bearings, and Sealed Power 4281M OE replacement bearings are commonly used by rebuilders looking for the correct fit.

What It Helps Address

• Worn or scored crankshaft main bearing surfaces
• Excessive main bearing clearance during engine rebuilds
• Loss of oil pressure related to bearing wear
• Noise or vibration from deteriorated main bearings
• Restoration work requiring standard-size Oldsmobile V8 bearings

Installation Notes and Tips

Verify crankshaft journal condition, housing bore measurements, and bearing size before assembly. Confirm the required standard or undersize selection against the engine’s machining specifications, since this set is offered in multiple size options. Clean all bearing saddles and journals thoroughly, and follow the engine builder’s torque and lubrication procedures during installation.

Fits 1964-1981 Oldsmobile Cutlass, N/A; fits 1968-1985 Oldsmobile Delta 88, N/A; fits 1977-1985 Oldsmobile Toronado, N/A; fits 1977-1984 Oldsmobile 98, N/A; fits 1977-1979 Pontiac Firebird, N/A.

Quality Assurance

Sealed Power states that its parts use innovative designs, advanced materials, and ISO & QS certified manufacturing to meet the demands of modern engines. The 4281M reflects that OE replacement focus for engine rebuilders who need consistent main bearing performance.