If the crankshaft runout readings on the dial indicator are plus .002 inch and minus .003 inch, how much runout is there?

To determine the total crankshaft runout, you need to consider the maximum displacement from the centerline of the crankshaft. The readings indicate that the crankshaft moves plus .002 inch in one direction and minus .003 inch in the opposite direction.

To find the total runout, you take the absolute values of both readings. The maximum displacement is determined by adding these two values together. In this case, .003 inch represents the greater deviation from the centerline, and .002 inch indicates the lesser deviation. Therefore, when you calculate the total runout, you take the distance from the maximum positive to the maximum negative, leading to a total runout of .002 inch (positive) plus .003 inch (negative), which equals .005 inch of total runout.

This overall runout measurement is crucial in evaluating the balance and functionality of the crankshaft, as excessive runout may lead to issues in engine performance and durability. Thus, the correct answer reflects the total extent of runout that the crankshaft exhibits.