Section 120-0010
Transmission - Transmission and Mounting
2
SM 1905 1-00
When the pump turns faster than the turbine, the
torque converter is multiplying torque. When the
turbine approaches the speed of the pump the stator
starts to rotate with the pump and turbine. When this
occurs, torque multiplication stops and the torque
converter functions as a fluid coupling.
Lockup Clutch
The lockup clutch is located inside the torque
converter and consists of three elements - piston,
clutch plate, and backplate. The piston and backplate
are driven by the engine and the clutch plate, located
between the piston and backplate, is splined to the
converter turbine.
The lockup clutch is hydraulically engaged and
released in response to electronic signals from the
ECU. It engages when the vehicle reaches a
predetermined speed. Engagement of the lockup
clutch provides a direct drive from the engine to the
transmission gearing. This eliminates converter
slippage to provide maximum fuel economy. The
lockup clutch releases at lower speeds (and
momentarily during shifts). When the lockup clutch is
released, drive from the engine is transmitted
hydraulically through the converter to the transmission
gearing. The lockup clutch also releases when the
ECU detects certain undesirable conditions.
Planetary Gears and Clutches
A series of planetary gears and shafts provide the gear
ratios and directions of travel for the vehicle. Power flow
through the planetaries is controlled by multiple clutch
packs. The clutches are applied and released hydraulically
in response to electronic signals from the ECU.
Hydraulic Retarder
A vaned rotor and two vaned stators are the basic
components of the retarder. Application of the retarder
control valve fills the cavity around the rotor with oil
when the vehicle must be slowed on steep
downgrades. When the cavity is emptied, the rotor is
free of drag. Refer to Section 250-0130, RETARDER
CONTROL VALVE.
Maximum retarder effect occurs in the lowest gear
range with foot off of the accelerator pedal. Long
continuous use of the retarder will raise transmission
oil temperature. Short periods of full release, to interrupt
continuous application, will help prevent overheating.
During normal operation the dash mounted
transmission oil temperature gauge should read in the
green zone. However, during transmission retarder
operation oil temperature can enter the yellow
'Retarder On' zone but should not enter the red zone.
Transmission Oil Cooler
The transmission oil is cooled by a separate oil cooler
mounted between the radiator and transmission to
maintain transmission oil within its required operating
temperature range. Refer to Section 210-0060,
TRANSMISSION OIL COOLER.
Transmission Oil Filter
The transmission oil filter is mounted off the frame at
the front right hand side of the transmission. It is
installed in the transmission oil lines to remove dirt and
other contaminants from the transmission oil to
minimise wear and provide maximum service life for
the transmission. Refer to Section 120-0100,
TRANSMISSION OIL FILTER.
REMOVAL
Numbers in parentheses refer to Fig. 1.
Note: Tag all lines, pipes, electrical connections and
mechanical linkages disconnected during removal to
aid in installation.
WARNINGS
To prevent personal injury and property
damage, be sure wheel chocks, blocking
materials and lifting equipment are properly
secured and of adequate capacity to do the job
safely.
High electrical current can cause sparks
and personal injury from burns. Switch circuit
breakers to the 'Off' position before removing
any electrical components. Remove battery
ground cable first, and reconnect last, to
prevent damaging electrical components.
Any time the battery equalizer is
disconnected from the batteries, remove
ground cable first, and reconnect last, to
prevent damaging the component.
1. Position the vehicle in a level work area, raise the
body and install the body prop pins. Refer to
Section 270-0010, BODY AND MOUNTING.
2. Apply the parking brake and switch off the engine.
Turn steering wheel several times to relieve pressure
in the steering circuit. Depress and release brake
pedal continuously to relieve pressure in the braking
system (pressure in accumulator hydraulic line should
be zero).
3. Block all road wheels.
To Next Page
Loading...
