For 1990-2009 cars

### Underbody Alignment Checking

Vehicles involved in an accident which may result in a bent frame, should be inspected for the following conditions:

• | Proper frame alignment

• | Steering geometry

• | Wheel alignment

The following are 2 different methods to determining vehicle measurements:

• | The tram gage method

• | The 3-dimensional method

### Tram Gauge Method

Use a tram gauge as a quick reference in order to determine vehicle damage. Include a vertical pointer capable of reaching 914 mm (36 in) when using the tram gage.

Measurements of the engine compartment components are generally made from point to point with the vertical pointers equally set.

Other measurements are made on the horizontal plane (datum line) parallel to the underbody with the vertical pointers set as specified for each point.

Measure the dimensions for the gauge holes to the center of the holes and flush to the adjacent surface metal unless otherwise specified. Cross-check diagonal dimensions in order to verify the dimensional accuracy of the vehicle underbody.

### Three Dimensional Method

Ensure that the repair equipment used for measuring structural repair is capable of measuring multiple points of length, width, and height simultaneously. Measure 2/3 of the vehicle body in order to obtain accurate comparisons of the vehicle structure.

Universal measuring systems combine the equipment and the techniques used in order to make underbody and upperbody 3-dimensional measurements. The universal system provides accurate measurements of length, width, and height measurements at the same time.

### Checking Frame to Body Alignment

Inspect the frame-to-body alignment by inserting a 16 mm (5/8 in) drill bit into the frame-to-body alignment holes.

Though the Oldsmobile and the Buick are different vehicles, the vehicles do share some common dimensions. All of the dimensions are measured in the metric system. Refer to General Information for the Metric-English conversion table if a conversion to English becomes necessary. Dimensions in the figures are given for the following 3 different measurements:

• | Length

• | Height

• | Width

Length dimensions are measured from the 0 point of the vehicle, and run toward the front and the rear of the vehicle along the horizontal plane. Width dimensions also run along the horizontal plane. The width dimensions originate from the centerline of the vehicle, and measure to the right or to the left, toward the side of the vehicle. Height dimensions originate at the datum line, which is a level surface from which vertical dimensions are measured. Before you install or realign the replacement components, level the vehicle and verify the dimensions using the height dimensions that have retained the original integrity of the structure.