TM 9-2330-294-14
NOTE
6-38. Assembly
Make sure that the heads of studs are firmly
a. Position drum on hub and aline markings made
in contact with drum after they have been
during disassembly (a above).
pressed in place. If a piece of paper can slip
NOTE
under the stud head, the stud is not properly
If a new drum and/or hub is assembled this
seated and must be pressed further. No
alinement is not necessary.
clearance is tolerable between stud head,
b. Aline holes in drum and hub and fit studs
drum face and hub face.
perpendicular (on centers of hub holes. Using arbor
press, install studs.
Section XI. WELD REPAIRS
this grade of steel be welded with low-hydrogen
6-39 General
electrodes. No preheat is recommended for 50,000 psi
The M747 semitrailer is fabricated from high-
yield strength steels.
strength. steel and aluminum alloys. These
NOTE
materials, although not new in the present state of
Weld repairs or replacement shall be per-
the art of high-strength metals, require qualified and
formed in accordance with TM 9-237, and as
experienced welders and procedures to prevent
specified herein. Paragraph 6-45 contains
degradation of material properties and to minimize
important supplementary repair information.
distortion which result from poor welding practices.
Requirements for weld repair of the different grades
of steel and aluminum used in the semitrailer are
The frame structure is fabricated from 50,000 psi and
generally adequately covered in TM 9-237. However,
100,000 psi yield strength steels as indicated in
the 50,00() psi yield strength steels, referred to as
H S L A (High-Strength, Low-Alloy), are not
used for weld repair of these steels are listed in table
referenced in TM 9-237. These steels are readily
6-4.
weldabie. For best results, it is recommended that
