GM Service Manual Online
For 1990-2009 cars only

Important: Jounce the vehicle 3 times before checking the alignment in order to eliminate false geometry readings.

Important: The caster angle must be corrected to the level frame angle.

Model

Caster (degrees)

Camber (degrees)

Sum Toe (degrees)

Z height (mm/in)

Steering Wheel Angle (degrees)

15 Series-Target

3.75

0.25

0.1

116 mm

(4.7 in)

0

15 Series-Allowable

2.75 to 4.75

-0.25 to +0.75

-0.1 to +0.3

110 to 122 mm

(4.3 to 4.8 in)

-5.0 to +5.0

25 Series-Target

4.50

0.25

0.1

116 mm

(4.7 in)

0

25 Series-Allowable

3.50 to 5.50

-0.25 to +0.75

-0.1 to +0.3

110 to 122 mm

(4.3 to 4.8 in)

-5.0 to +5.0

    • Down in the rear frame angles must be subtracted from a positive caster reading.
    • Up in the rear frame angles must be added to a positive caster reading.
    • Down in the rear frame angles must be added to a negative caster reading.
    • Up in the rear frame angles must be subtracted from a negative caster reading.

Object Number: 156339  Size: SH
    •  The front suspension Z dimension (4) is held as indicated.
    • The left side and the right side are to be equal within 0.50 degrees.
    • The left side and the right side are to be equal within 1.0 degrees.
    • The toe-in left side and the right side are to be equal per wheel and the steering wheel, must be held in a straight ahead position within 5.0 degrees.

Steering Wheel Pull

    • The target figure for steering wheel pull is a cross camber/cross caster reading of zero.
    • Use the cross camber and cross caster figures from your alignment equipment and compare them with the following charts. The shaded areas are within the allowable specification for steering wheel pull.

15 Series Vehicles


Object Number: 623022  Size: MF
(1)Cross Camber in Degrees
(2)Cross Caster in Degrees

25 Series Vehicles


Object Number: 625323  Size: MF
(1)Cross Camber in Degrees
(2)Cross Caster in Degrees