GM Service Manual Online
For 1990-2009 cars only

Plane


Object Number: 264982  Size: SH

A centerline is an imaginary vertical plane that is perpendicular to the length of the datum plane through the center of the vehicle. The centerline is any line drawn through the center of the vehicle's datum. The symbol for centerline is CL.

Length

Centerline length measurements are 3-dimensional measurements. The three dimensions are the following:

    • Length, the distance between 2 points when the height is parallel to the center plane.
    • Height, the measurement is parallel to the datum plane.
    • Width, the measurement is parallel to the center plane.

When reading dimension charts, horizontal width and length dimensions of the underbody are shown as viewed from the bottom of the underbody. Vertical dimensions are shown from the side of the underbody and use the datum plane as a base for all vertical (height) measurements.

Centerline measurements are used with universal measuring equipment.