Service Bulletin 1M-157
Figure 1 Typical 37-MT motor.
The pinion is moved into mesh with
The bolts should be torqued to 13-
Heavy duty cranking motors have a
the ring gear by the action of the
17 lb. ft. during reassembly. In this
The pinion remains
type of assembly, the lever housing
that are totally enclosed to protect
engaged until the solenoid circuit is
and the commutator end cap are
them from exposure to dirt, icing
attached to the field frame
conditions and splash. The nose
independently by bolts entering
housing can be rotated to obtain a
threaded holes in the field frame.
number of different solenoid
Under normal operating conditions,
positions with respect to the
no maintenance will be required
mounting flange. High durability
There are many different cranking
between engine overhaul periods.
features include a newly designed
motor circuits used on various ap-
At time of engine overhaul, motors
The cranking circuit
should be inspected, cleaned, and
and one-piece brushes which
may contain a key start switch or
tested as described in succeeding
provide extra long brush life. Also,
push switch, or both, a relay,
the commutator end cap can be re-
magnetic switches, solenoids, oil
moved to inspect the brushes.
ADJUSTABLE NOSE HOUSING
pressure switch, fuel pressure
As shown in the cross-sectional
Lubrication is provided in the
views of Figure 2, the nose
sintered bronze bushings by an oil
devices, such as an "ADLO" relay.
housing is attached to the lever
saturated wick. Oil can be added
housing by means of bolts located
Reference should be made to
to each wick by removing an oil
around the outside of the housing.
the ATEC electrical schematics
reservoir cup which is accessible
To relocate the housing, it is only
in TM 5-3810-307-24-1-1.
on the outside of the motor.
necessary to remove the bolts,
rotate the housing to the desired
position, and reinstall the bolts.