21-4. FRAME INSPECTION AND REPAIR (Cont'd)
Visual inspection. This is the first and most critical step in forming the decision of whether to
repair or replace a damaged frame component. Factors to be noted in visual inspection:
(a) Transverse tears, cracks, and breaks that extend over one tangent or radius and into 5/32 in.
(3.97 mm) of an associated tangent or radius must be replaced (refer to view A).
(b) Transverse tears, cracks, or breaks that extend over the tangent or radius can be repaired by
welding and reinforcing, providing the crack does not extend into 5/32 in. (3.97 mm) of an
associated tangent or radius (refer to view B).
(c) Tears, cracks, or breaks on the inside face of the frame rail that extend to within 3 in. (7.6 cm)
of a bolted-on crossmember are unrepairable, and frame rail must be replaced.
(d) Tears, cracks, or breaks that extend into a hole or from a hole in the frame rails must first
have a dye penetrant test performed at the hole to determine if secondary cracks exist (refer to
TC 9-237). The crack is unrepairable if a secondary crack exists; the frame rail must be
replaced (refer to view C).
(e) Tears, cracks, or breaks that extend into a hole or from a hole that does not have any existing
secondary cracks may be repaired by welding with the use of a pre-drilled reinforcement
(dutchman/ fishplate) (refer to view B and task e).
(f) Short longitudinal cracks (up to 6 in. (15.2 cm)) or split welds can be repaired by installing a
reinforcement (dutchmen/fishplate) and heli-arc welding (refer to view B).
(g) Twisted frame rails are unrepairable; replace (refer to view C).
Measurements. Select a hard and level surface with area 1-1/2 times the size of the vehicle.
(a) Vertical (or side view) measurement.
(1) Raise vehicle at four points until all four wheels are off the surface.
(Refer to TM 9-2320-280-20).
Shim material must be under jackstand. Do not use shims on top
of jackstand. Vehicle could be knocked off jackstand, causing
personnel injury or damage to equipment.
Measure the height to the bottom of frame near each jackstand. Place shim(s) under
jackstands as necessary until all four heights are equal.
Measurements must be taken at identical locations on left and
right frame rails. Failure to do so will result in faulty indication.
Select, measure, and record the frame rail height at several different positions on either
Measure and record frame rail height at corresponding points on opposite frame rail.
Right and left frame rail comparable points deviating more the 1/8 in. (3 mm) for each 2 ft
linear distance indicates a vertically bent frame. Record deviations.
If measured frame rails are out of tolerance, notify supervisor. If
frame rails are verified to be out of tolerance, vehicle will be
classified as unserviceable.
Lower vehicle from jackstands. (Refer to TM 9-2320-280-20).