CHEVROLET,GMC L20(4.8L)V8 Crankshaft – OE 12553482

Overview

Replacement L20(4.8L)V8 crankshaft for CHEVROLET,GMC applications, referenced against OE 12553482. Built as a service part for engine overhaul, it replaces a worn or damaged original crankshaft rather than modifying the existing one.

Engine application

• Engine code: L20(4.8L)V8
• Listed for: CHEVROLET,GMC
• OE references: 12553482

How this part fails

Crankshaft damage is usually a consequence rather than a cause: a spun bearing, a blocked oil way, detonation or a failed oil pump takes the journals out of tolerance. The usual signs are a rhythmic knock that follows engine speed, dropping oil pressure, and metal paste or flakes in the oil filter. Journal scoring beyond the undersize limits means replacement rather than regrinding.

Specifications

Fitment checks before ordering

Verify fitment by engine code and OE number, not by model year or capacity. If your engine is a L20(4.8L)V8 variant but your OE number is absent from this list, treat the part as unconfirmed and ask before ordering.

Rebuild notes

Before assembly, measure every main and big-end journal for diameter, taper and ovality, and check thrust and runout. Bearings must match the journals as supplied. It is normal practice to renew the rear seal, flush the oil galleries and inspect the oil pump at the same time, then verify clearances with plastigauge during assembly.

What is included

One crankshaft is supplied. Rebuilding an engine also requires bearings, seals and fasteners, which are not part of this listing.

Availability and warranty

The listing does not publish a stock quantity, so availability is confirmed by the supplier at order rather than shown here. The current Alibaba listing quotes delivery by Dec 28. The manufacturer states a 1 year or 10,000 KM, whichever comes first warranty on this listing.