Transmission Description - System Operation And Component Description (G1550394): Description: Notes
The transmission comprises the main casing which houses all of the transmission components. The main casing also incorporates an integral torque converter housing.
On 2.2L DW12C models the transmission casing has a foam NVH (noise, vibration and harshness) cover over the torque converter housing.
A fluid pan is attached to the lower face of the main casing and is secured with bolts. The fluid pan is sealed to the main casing with a gasket. Removal of the fluid pan allows access to the Mechatronic valve block. The fluid pan has magnets located at the rear which collects any ferrous metallic particles present in the transmission fluid.
A fluid filter is located inside the fluid pan. If the transmission fluid becomes contaminated or after any service work, the fluid pan with integral filter must be replaced.
The transmission does not have a Bowden cable for park lock operation. This is initiated electronically when the TCS is moved to the 'P' park position. An emergency park interlock release mechanism is provided to release the park interlock if a failure occurs.
A new feature of the 8 speed transmission is decoupling of the transmission when the vehicle is at a standstill. Normally the transmission remains in gear with the torque converter slipping and the vehicle is prevented from moving by applying the brake. The new system disengages one of the transmission clutches and only a minimum rotating load remains. This has the effect of further reducing fuel consumption.
The internal oil pump is driven by a simplex chain and 2 drive gears from the torque converter. The oil pump is a double stroke vane cell pump which delivers 50 cm3 of transmission fluid per revolution.
The integral torque converter housing provides protection for the torque converter assembly and also provides the attachment for the gearbox to the engine. The torque converter is a non-serviceable assembly which also contains the lock-up clutch mechanism.
The main casing contains the following major components:
- Input shaft
- Output shaft
- Mechatronic valve block which contains the solenoids, speed sensors and the TCM
- Three rotating multiplate drive clutches
- Two fixed multiplate brake clutches
- Four planetary gear trains.