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TRUCK SERVICE MANUAL
TM 5-4210-230-14&P-1
FRAMES
Important
In addition to the specific recommendations given in
these paragraphs, always remember the following general
rules of welding "good housekeeping".
1.
Surface areas and edges to be joined must be clean
and free of oil or grease.
2.
Always avoid craters, notching, and undercutting.
3.
Peen new welds to relieve stresses caused by
shrinkage.
Positioning of Frame Reinforcements
Whenever practical, the welding of frame reinforcements
should be confined to the web of the side rail rather than the
flanges. This procedure provides the strongest possible
assembly.
Avoid at all times welds made square with the side rail,
either on webs or flanges. When welds are made at an angle
of at least 30 degrees from square, there is less possibility of
setting up dangerous stress concentrations in the rail.
Physical tests of the strength of various welds have shown
that a weld made at an angle of at least 30 degrees from the
direction of strain will retain the original physical properties of
the complete rail section.
Frame Straightening Use of heat is not recommended
when straightening frames. Heat weakens the structural
characteristics of frame members and all straightening should
be done cold. Frame members (except aluminum) which are
bent or buckled sufficiently to show cracks or weakness after
straightening, should be replaced or reinforced.
Repair and Reinforcements
(Aluminum Alloy Frames)
The cutting and welding of aluminum alloy frames for
repair or reinforcement can be accomplished providing correct
procedures are followed and proper welding equipment is
utilized. The use of heat for straightening aluminum frame
rails is not recommended.
BOLT SPECIFICATIONS AND TORQUES
While most IH frames are of riveted construction, there
are some frames which are assembled with bolts and nuts.
Bolting,
though more costly does provide the field with a time saving
advantage when replacing crossmembers or frame attaching
parts.
If bolting is used for altering or adding to the frame, the
following precautions must be observed.
NOTE: Bolts to be used for installing fifth wheels must be
5/8" diameter high strength material such as I. H. Type 8
(SAE grade 8) bolts. Type 8 bolts can be identified by the six
radial lines on the head of the bolt. Nuts must be of
corresponding type.
The torque value for tightening these bolts is 220-250 ft.
lbs. and is based on new bolts and nuts lubricated with
engine oil. If frame components are aluminum, flat washers
must be used next to the aluminum whether under head, nut
or both.
Proper tightening of bolts and nuts is most important,
since the strength of the joint depends on the maximum
clamping force between the members.
REPAIR AND REINFORCEMENTS
(Heat Treated Frames)
With the use of heat treated frame rails in International
vehicles, it becomes advisable to outline some of the
procedures to be followed whenever these frames require
repair.
Heat treated frame rails must not, of course, be
intermixed with non-heat treated rails. If one side rail is to be
replaced, the new rail material must match the old frame rail.
Preparation Of Frame For Repair
A good method to follow when repairing a cracked frame
where the crack is accessible from both sides is as follows:
a.
Grind a V notch or groove extending along the full
length of the crack and slightly beyond each end of
the crack. A heavy copper strip or "chill" should be
clamped to the rail side away from the groove to help
control the temperature and cooling rate. See Fig.
7. NOTE: Discarded short lengths of heavy copper
electrical
bus
bars
make
suitable
chills.
CTS-2037-HA Page 5
PRINTED IN UNITED STATES OF AMERICA
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