A camshaft gear is usually precisely positioned on the camshaft using a?

A camshaft gear is typically secured on the camshaft through the use of a key and keyway. This method ensures that the camshaft gear maintains its position relative to the camshaft, allowing for precise timing and synchronization with the engine's crankshaft. The key fits into a slot or keyway on both the camshaft and the gear, preventing any relative rotation between the two components.

This precision is critical in engine performance, as even slight misalignment can lead to timing issues that affect the engine's power output and efficiency. The use of a key and keyway establishes a mechanical connection that withstands the stresses and forces encountered during operation, ensuring the gear stays securely in place under various operating conditions.

Other options, while important in different contexts, do not serve this purpose as effectively. An interference fit relies on tight tolerances and friction to hold components together; however, it may not allow for easy disassembly. A captured thrust washer is typically used to manage axial loads and does not ensure precise positioning of the gear. A dial indicator is a measuring tool used for precision setups, but it does not secure components together. Thus, the key and keyway method is essential for maintaining the correct relationship between the camshaft and its gear.