Tram Gage Method
WARNING: This page is about a different car, the 2005 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
A tram gage is a quick reference for determining vehicle damage. The tram gage set requires a vertical pointer that is capable of reaching 914 mm (36 in).
Measure the engine compartment components from point to point using the equally set vertical pointers.
Use the vertical pointers in order to make other measurements on the horizontal plane or the datum line, parallel to the underbody. Ensure that the pointers are set as specified for each point.
When measuring dimensions to the gage holes, measure to the center of the holes flush to the adjacent surface metal. Cross-check the diagonal dimensions in order to verify the dimensional accuracy of the vehicle underbody.