Automatic Transmission
The automatic transmission comprises the main casing which houses all of the transmission components. The main casing also incorporates an integral 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 Automatic Transmission Fluid (ATF).
A fluid filter is located inside the fluid pan. If the ATF becomes contaminated or after any service work, the fluid pan with integral filter must be replaced.
The transmission does not have mechanical connection for park lock operation from the passenger compartment. This is initiated electronically when the Transmission Control Switch (TCS) is moved to the Park (P) position. An Emergency Park Release (EPR) mechanism is provided to release the park interlock if a failure occurs.
A new feature of the eight 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 ATF pump is driven by a simplex chain and two drive gears from the input shaft. The ATF pump is a double stroke vane cell pump which delivers 50 cm3 of ATF per revolution.
The integral torque converter housing provides protection for the torque converter assembly and also provides the attachment for the transmission 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 Transmission Control Module (TCM)
- Three rotating multiplate drive clutches
- Two fixed multiplate brake clutches
- Four planetary gear trains.
Transmission Sectional View
| ITEM | DESCRIPTION |
|---|---|
| 1 | Transmission casing |
| 2 | Gear set 1 |
| 3 | Gear set 2 |
| 4 | Gear set 3 |
| 5 | Gear set 4 |
| 6 | Output shaft |
| 7 | Drain plug |
| 8 | Clutch D |
| 9 | Clutch C |
| 10 | Clutch E |
| 11 | Mechatronic valve block |
| 12 | Brake B |
| 13 | Brake A |
| 14 | Fluid filter |
| 15 | Fluid pan |
| 16 | Automatic Transmission Fluid (ATF) pump |
| 17 | Torque converter |
| 18 | Input shaft |