TM 9-2320-361-34 13-3. FRAME ALINEMENT INSPECTION (Contd) 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. 7. Place string over grease fitting (2) on left 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 make mark on paper until plumb bob has stopped swinging and is close to, but not touching, paper. 8. Carefully mark spot (3) on paper directly below plumb bob point. 9. Measure distance between left side plumb bob mark (3) and string on floor (4). If distance is more than 1/4 in. (6 mm), frame rails (5) are out of tolerance. NOTE ● If measured frame rails are out of tolerance, notify supervisor. If frame rails are verified to be out of tolerance, truck will be classified as unserviceable. ● At end of inspection, remove plumb bob and string. 13-8