Crankshaft bearings — more precisely main journal bearings — form the thin-wall shell inserts that sit between the crankshaft main journals and the bearing bores in the engine block, providing a precision oil film that keeps the crankshaft rotating freely under enormous combustion loads without metal-to-metal contact. Unlike most service parts, crankshaft bearings rarely fail through normal wear alone; the most common causes of premature bearing failure are oil starvation from delayed oil changes, oil aeration from a faulty sump baffling, or the use of an incorrect viscosity grade that breaks down the hydrodynamic film at operating temperature. The audible symptom is a deep, rhythmic knocking from the bottom of the engine — a sound that intensifies under load and cannot be confused with valve train noise. MAHLE and KOLBENSCHMIDT manufacture the majority of original-equipment crankshaft bearing sets used in European engines and maintain the same OE specifications in their service parts. KING also covers a comprehensive range across BMW, Volkswagen, Ford, and Hyundai platforms. Because bearing wall thickness, overlay material, and crush height are specific to each crankshaft family, using the OE-referenced set is essential to maintaining the correct oil clearance.
Crankshaft bearings are specified by journal diameter, bearing wall thickness, and overlay material type — all of which are specific to a particular engine block casting and crankshaft variant. Standard-size bearings are fitted from the factory; if the crankshaft has been reground during a previous overhaul, undersized bearings in increments of 0.25 mm are required. Each listing on this page shows the OE reference TecDoc assigns to your make, model, year, and engine code. Consulting the engine's workshop manual for the correct size code before ordering prevents fitting a standard-size bearing on an undersize crankshaft journal.
OEM crankshaft bearings — the majority produced by MAHLE and KOLBENSCHMIDT to engine manufacturer specifications — use tri-metal or bi-metal constructions with overlay alloy compositions calibrated for the specific oil film pressures of each engine. Quality aftermarket sets from KING and GLYCO are designed and tested to the same dimensional and material standards. Budget bearings sometimes use thinner overlay layers with lower fatigue strength, which accelerates the transition from minor surface damage to bearing spin under the dynamic loads of a running engine, causing catastrophic crankshaft damage.
In some cases yes, though the scope of work is substantial. With the engine in the vehicle, the sump must be removed to access the main bearing caps. Each cap is removed one at a time, the old shell extracted, the journal surface and housing bore inspected for scoring, and a new shell set fitted. The crankshaft is not removed unless the journals require regrinding. This in-situ replacement is practical if the journals are in good condition and the failure was caused by oil starvation rather than mechanical damage. Any scoring on the crankshaft journal surface requires removal and regrinding before new standard-size bearings will seal correctly.
The definitive symptom is a deep, repetitive knock from the base of the engine that is timed to the crankshaft rotation — it occurs once per revolution and becomes louder as engine speed increases and under load conditions such as climbing a hill in a high gear. Low oil pressure at idle, shown by a flickering oil pressure warning light, is often the preceding condition rather than a consequence. A metallic sheen in the engine oil at an oil change — small particles in the drain — indicates bearing material has already begun to shed. Ignoring these signs typically ends in crankshaft journal damage within weeks.
Showing 100 of 1,959 Crankshaft Bearing OE numbers. Enter the OE on the main OE search to jump to any reference.
