TM
11-2320-60-34-2
13-6. FRAME ALINEMENT INSPECTION (Contd)
c. Frame Squareness
1. Locate and clean two front grease fittings (3) on right and left front spring shackles (4).
2. Tape a 8 x 10.5 in. (20 x 27 cm) sheet of white paper to floor under right and left front spring
shackles (4).
NOTE
Ensure plumb bob is placed toward front of truck on both right
and left grease fittings. If not, inaccurate measurement of frame
squareness will result.
3. Place string over grease fitting (3) on left front spring shackle (4) with plumb bob toward front of
truck. Lower plumb bob and locate point on paper below spring shackle (4).
NOTE
Do not mark paper until plumb bob has stopped swinging and is
close to, but not touching paper.
4. Carefully mark spot on paper directly below plumb bob point.
5. Place one edge of square along horizontal line (2) used to measure horizontal bow on right side of
truck, and other edge of square touching plumb bob mark.
6. Stretch string along edge of square to right side of truck. Allow string to extend 6 in, (15 cm) beyond
right horizontal line (2). Secure or tape string to floor.
7. Repeat steps 3 and 4 for right front spring shackle.
8. Measure distance between right side plumb bob mark and string on floor. If distance is more than
0.25 in. (6 mm), frame rails (1) are out of tolerance.
If frame rails are verified to be out of tolerance, notify your super-
visor. If frame rails are out of tolerance, truck will be classified as
unserviceable.
13-28
