Figure 7-23.Removing the governor assembly.
TRANSMISSION OVERHAUL. Because of the
complexity of automatic transmissions, the need for
special tools, and personnel skills, overhauling these major
components is usually done at a Construction Equipment
Department located at a Construction Battalion Center.
Overhaul of automatic transmissions is not a job for an
inexperienced person. If the job must be performed in the
field, it is recommended that only a highly capable
mechanic be assigned to this type of work NCIC, Port
Hueneme, Calif., and NCTC, Gulfport, Miss., both offer
training in automatic transmission overhaul as part of the
12 week CM-C-1 advance course.
The following disassembly instructions apply to the
General Motors Turbo Hydra-Matic Model 400 series
automatic transmission. This type of transmission is
commonly found in CESE throughout the NCF and in
Figure 7-24.Removing the filter assembly.
many public works stations. It is likely to be in
manufacture for years to come.
Before preceding with automatic transmission
disassemble y or reassembly, get the applicable repair
instructions and have them on hand. READ THIS
INFORMATION !!!!! Incorrect disassembly
procedures can lead to severe parts damage, causing
unnecessary equipment downtime. Have a workplace
away from the main CM shop. A dust-free
air-conditioned room is the best, but this is not always
available. Obtain the cleanest work space possible!
Have on hand any special tools needed for the job, such
as snap ring pliers, torque wrenches, or special pullers.
It is also a good idea to have an air compressor available
for test purposes and for blowdrying individual parts.
Compressed air used for cleaning purposes
should not exceed 30 psi. Wear goggles and
other appropriate protective equipment when
you use compressed air.
Clean the outside of the transmission and drain out
as much fluid as possible. Remove the torque converter
and set it aside for separate cleaning and testing. Place
the transmission on the workbench and remove the
governor (fig. 7-23). Next, remove the oil pan, oil filter,
and intake pipe (fig. 7-24). The type of debris found in
the bottom of the oil pan is indicative of the type of
internal damage you may find in the transmission.
Remove the vacuum modulator and valve (fig. 7-25);
Figure 7-25.Removing the vacuum modulator.