GM Service Manual Online
For 1990-2009 cars only

    Important: When measuring alignment angles, it is critical that vehicle curb trim height be correct. Measure and adjust trim height according to the following procedure before performing alignment.

  1. Place vehicle on a level surface.
  2. Adjust tire pressures to correct specifications.
  3. Curb trim height should be measured with:
  4. • 207 kPa (30 psi) tire pressure -- front tires
    • 179 kPa (26 psi) tire pressure -- rear tires
  5. If vehicle fuel tank is not full, the following chart may be used to determine amount of weight necessary to be added to the trunk of vehicle to simulate a full fuel tank.
  6. Fuel Level - Weight to Add

    • 1/8 -- 31.8 kg (70 lb)
    • 1/4 -- 27.2 kg (60 lb)
    • 3/8 -- 22.7 kg (50 lb)
    • 1/2 -- 18.1 kg (40 lb)
    • 5/8 -- 13.6 kg (30 lb)
    • 3/4 -- 9 kg (20 lb)
    • 7/8 -- 4.5 kg (10 lb)
  7. Bounce front and rear suspensions a few times to settle suspension.

  8. Object Number: 859336  Size: SH
  9. Measure front and rear vehicle curb trim height.
  10. • Measure from the front (A) or the rear (B) of the rocker flange to locate the curb trim height measuring points (J) and (K).
    • Measure curb trim height from the level surface the vehicle rests on to the bottom horizontal surface of the rocker panel.

       Important: Do not measure from rocker/jacking flange.

Model

A

B

Sedan/Wagon

117 mm (4.6 in)

105 mm (4.1 in)

Coupe

150 mm (5.9 in)

138 mm (5.4 in)

Curb Trim Height

J

K

Model

Front Rocker Height Range

Rear Rocker Height Range

Sedan

201-233 mm (7.8-9.0 in)

202-234 mm (8.0-9.3 in)

Coupe

200-232 mm (7.8-9.1 in)

201-233 mm (7.9-9.4 in)

Wagon

201-233 mm (7.8-9.1 in)

202-234 mm (8.1-9.5 in)