CAUTION
Oil drained from automatic transmissions contains heavy metals and is considered
hazardous waste and should be disposed of according to local instructions
.
Once the oil is drained, remove the pan completely for cleaning by paying close
attention to any debris in the bottom of the pan. The presence of a high amount of metal
particles may indicate serious internal problems. Clean the pan, and set it aside.
All automatic transmissions have a filter or screen attached to the valve body. The
screen is cleanable, whereas the filter is a disposable type and should always be
replaced when removed. Screens and filters are retained in different ways: with
retaining screws, with metal retaining clamps, or with O-rings made of neoprene. Clean
the screen with solvent and use low-pressure air to blow-dry it. Do not use rags to wipe
the screen dry, as they tend to leave lint behind that will be ingested into the hydraulic
system of the transmission. If the screen is damaged or is abnormally hard to clean,
replace it.
Draining the oil from the pan of the transmission does not remove all of the oil-draining
the oil from the torque converter completes the process. To do this, remove the torque
converter cover and remove the drain plug, if so equipped. For a torque converter with-
out a drain plug, special draining instructions may be found in the manufacturer's
service manual. Before performing this operation, clear it with your shop supervisor.
2.5.1.4 Refilling the Transmission
Reinstall the transmission oil pan, the oil plug, and the fill tube. Fill the transmission with
the fluid prescribed by the manufacturer to the proper level. With the brakes applied,
start the engine and let it idle for a couple of minutes. Move the gear selector through all
gear ranges several times, allowing the fluid to flow through the entire hydraulic system
to release any trapped air. Return the selector lever to park or neutral and recheck the
fluid level. Bring the fluid to the proper level. Run the vehicle until operating temperature
is reached, checking for leaks. Also, recheck the fluid and adjust the level as necessary
.
CAUTION
Overfilling an automatic transmission will cause foaming of the fluid. This condition
prevents the internal working parts from being properly lubricated, causing slow
actuation of the clutches and bands. Eventually, burning of the clutches and bands
results. Do
NOT
overfill an automatic transmission
.
2.5.2 ng
Good troubleshooting practices save a lot of time and money for the Navy. If you know
what you are doing when you troubleshoot an automatic transmission, you should be
able to pinpoint the problem before you remove it from the vehicle. In some cases, you
may be able to make the repairs without removing the transmission.
Before troubleshooting the transmission, make sure the engine is in good running
condition. An engine that is not operating properly will not allow the transmission to
function normally
.
NOTE
A malfunction may have more than one probable cause. Complete all the tests and
inspections for each cause to find the correct cause.
NAVEDTRA 14050A
7-17