What is the procedure for checking king pin wear?

The procedure for checking king pin wear involves making sure that the load is properly addressed when measuring the deflection of the king pin assembly. Removing the weight from the spindle ensures that the suspension system is not under compression, allowing for accurate measurement of any potential deflection caused by wear on the king pin.

By prying up under the tire, any vertical movement can be observed and quantified. This measurement of deflection is critical because it translates directly to wear on the king pin. A significant amount of vertical movement may indicate that the king pin or bushings are worn, which could affect steering and handling of the vehicle.

In contrast, the other options do not provide a reliable method for determining king pin wear. Some involve measuring deflection while the suspension is loaded, which can lead to inaccurate readings since the weight could mask any play in the king pin. Others might not directly measure the vertical travel related to king pin integrity, further underscoring the importance of checking while the weight is removed to obtain clean, accurate data. Therefore, the correct answer effectively addresses the procedure required for an accurate assessment of king pin wear.