TM 9-2320-361-34 13-3. FRAME ALINEMENT INSPECTION (Contd) I d. Frame Squareness 1. Locate and clean two front grease fittings (2) on right and left front spring shackles (1). 2. Tape an 8 x 10-1/2 in. (20x 27 cm) sheet of white paper to floor (4) under right and left front spring shackles (1). 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 (2) on right front spring shackle (1) with plumb bob toward front of truck. Lower plumb bob and locate a point on paper below spring shackle (1). NOTE Do not mark paper until plumb bob has stopped swinging and is close to, but not touching, paper. 4. Carefully mark spot (3) on paper directly below plumb bob point. 5. Place one edge of square (7) along horizontal line (6) used to measure horizontal bow on right side of truck and other edge of square (7) touching plumb bob mark (3). 6. Stretch string along edge of square (7) to left side of truck. Allow string to extend 6 in. (15 cm) beyond left horizontal line (5). Tape or secure string to floor (4). 13-6