Section III. GENERAL MAINTENANCE
2-5. General Removal and Disassembly Instructions
b. Smooth any rough edges on which a seal, gasket or
Prior to attempting any disassembly procedures the
packing will seat.
following points should be read and adhered to.
c. Smooth out all nicks, burrs, or rough spots on
Make sure crane is properly shut-down, blocked
shafts, bores, pins or bushings.
and supported (as required for safety) prior to performing
2-8. General Reassembly Instructions
any maintenance functions.
a. Insure that bearing assemblies have been pre
Always make use of suitable slings, jacks, and
packed with suitable bearing grease.
supports when removing heavy assemblies.
b. Never force a bearing on a shaft if the fit is
Always try to provide a clean working area
exceedingly tight. Polish the shaft and heat the
especially when disassembling engine, engine
bearing. To heat the bearing, immerse it completely in
accessories, transmissions, axles, wheels, assemblies
an oil bath or heat in an oven.
and similar sealed and lubricated sub-assemblies.
c. Insure that bearings and spacers are reassembled
When an assembly has been removed,
in the same position and order in which they were
immediately re-install attaching hardware to prevent
losing those parts.
d. Always use a torque wrench when specified.
Insure that all hoses, tubes and wiring
2-9. Welding Procedure for "T-1" Steel
assemblies are properly tagged or otherwise identified to
a. General. The upper turret flange is the only place in
insure proper reassembly and installation.
this machine where high strength "T-1" steel is used.
Disassembly should be limited to the point
The following instructions cover the methods to be
required for repair or replacement. The exception to this
used in welding this high strength alloy steel.
is for further inspection of the assembly.
b. Electrode Selection. The single most important thing
ever use a torch to remove any part unless the
to remember in the welding of high strength steels is to
part to be removed is already damaged and the heat will
use the right electrode. Be sure to use only electrodes
not damage any surrounding parts. If a screw, bolt or
with "low-hydrogen" coatings for manual arc welding.
nut is hard to remove, try a rust removing fluid or
An alternative method would be to use a welding
lubricant before using excessive heat or force.
method, such as inert gas shielded arc, or submerged
Refer to figure 2-1 to remove any sheet metal
arc, which is inherently "low-hydrogen." Hydrogen is
required to gain access to component or assemblies
the main cause of failure in welding high strength alloy
steel. Hydrogen which remains in the weld will cause
2-6. General Cleaning and Inspection Instructions
cracking when the welded steel cools. This cracking is
In general, any part that has been removed and/or
not visible at the surface of the weld, but will occur
disassembled should be cleaned and inspected as
beneath the visible surface. In order to insure the
proper selection of low-hydrogen rods, use rods with
a. Clean all parts using a suitable cleaning solvent such
classification numbers ending in 15, 16, 18, or 28.
as Federal Specification P-D-680. A scraper or steel
Samples of acceptable rods are E7028, E8015, E9016,
brush may be required on some external components.
and E11018. When welding "T-1" steel to a lower
Dry all parts thoroughly. Lubricate those assemblies that
strength steel, the electrode strength should be the
same as recommended for the lower strength steel,
b. Inspect all parts that receive torque or other strain for
but must remain of the low-hydrogen type. Also, when
cracks, bends or excessive wear.
doing submerged-arc or inert-gas welding, the wire or
c. Inspect gears for worn, cracked or chipped teeth.
wire-flux combination need only match the lower
d. Inspect all bearings, bushings and sleeves for
strength steel. Correct handling of electrodes, fluxes,
excessive wear, scoring or other damage.
and shielding gases is also very important. Low-
e. Inspect threaded parts for damaged threads. f
hydrogen coated electrodes and fluxes, when exposed
Inspect, carefully, all seats in which a seal gasket or
to the air, will pick up moisture. Moist coating will
packing will seat for rough edges.
generate underbead cracking, even though, when dry,
g. Inspect any passages and grease fittings to insure
they are classified as "low-hydrogen." Make sure the
that they are clean and open.
electrodes are dry as follows:
2-7. General Repair and Replacement Instructions
(1) If your electrodes are in an undamaged metal
Replace all oil seals, gaskets and preformed
container and you are sure the container was air tight
packings. Make sure replacement gasket is the same
before opening, put the electrodes immediately into a
thickness as the old gasket.
ventilated holding oven set at 250/300F. Note that
moisture control in E70 rods is not as good as in higher
strength rods, and it is therefore particularly strength
rods, and it is therefore particularly impor-