Which factor should be assessed to check flywheel installation?

When installing a flywheel, assessing the flywheel runout is critical to ensuring proper engine operation. Runout refers to the amount of deviation from a perfectly circular shape when the flywheel is rotated. A certain level of runout is acceptable, but excessive runout can lead to problems such as vibration, clutch engagement issues, and uneven wear of the clutch components.

Proper checking of the flywheel runout is generally performed using a dial indicator to measure any variations in the flywheel surface as it spins. If the runout exceeds the manufacturer's specifications, it may require machining or replacement to ensure smooth operation and alignment with the engine components.

The other factors, while they may have some relevance, do not directly impact the immediate performance and alignment of the flywheel in the way that runout does. For example, while flywheel thickness is important for compatibility with the clutch assembly, it does not directly relate to the performance in terms of vibration and alignment. The color and weight of the flywheel do not play significant roles in its installation or function and are typically not factors that would affect engine performance.