When replacing main bearings on an engine, what should be checked after torquing each main bearing cap?

When replacing main bearings on an engine, it's vital to ensure that the crankshaft can rotate freely after the main bearing caps have been torqued. This is indicative of proper alignment and clearance within the crankshaft's bearing surfaces. Ensuring free rotation helps to confirm that there are no obstructions or excessive tightness, which could lead to severe engine damage, increased friction, or even a complete engine failure if not addressed.

Checking the free rotation of the crankshaft involves manually turning the crankshaft to ensure it can move smoothly and without binding. If the crankshaft does not rotate freely, it indicates potential issues such as improper bearing installation, debris or foreign objects preventing movement, or alignment issues that could affect engine operation.

Other options can be relevant in different contexts but do not directly address the immediate need to confirm that the main bearing installation allows for the crankshaft to move properly after torquing the caps. For example, clutch free pedal measurement pertains to the clutch system, while crankshaft deflection and connecting rod side clearance are typically checked during different stages of engine assembly or maintenance rather than immediately after tightening the main bearing caps.