DESCRIPTION
The continuously variable transmission (CVT) has a torque converter and allows optimal driving force in response to the accelerator pedal operation, therefore giving us smooth driving without shift shock. The CVT also has a manual mode function for both smooth driving without shift shock, and enjoyable driving with manual ratio selection.
The CVT allows for maximum driving force and performance when compared to a conventional A/T. When the throttle is fully opened, driving force for the conventional automatic transmission changes unevenly because the ratio is shifted in steps. On the other hand, driving force for the CVT changes smoothly because it is possible for it to accelerate while keeping it in the peak power range of the engine. Therefore, CVT avoids the loss of driving force, and enables smooth and shock free driving.
Coordinated control of the engine and the multifaceted shift diagram have made it possible to realize both, smooth and powerful driving with a good ratio change response and an improvement in fuel consumption.
Scheme 1
| 1 - REVERSE BRAKE (RELEASED) |
|---|
| 2 - FORWARD CLUTCH (RELEASED) |
| 3- PARKING GEAR (FIXED) |
When the forward clutch and the reverse brake are released, the driving force from the engine runs idly and power is not transmitted to the primary pulley.
When the parking gear is fixed, the torque load from the tires is not transmitted up to the primary pulley.
Scheme 2
| 1 - REVERSE BRAKE (ENGAGED) |
|---|
| 2 - FORWARD CLUTCH (RELEASED) |
When the reverse brake is engaged, the planetary carrier is fixed and the driving force from the engine rotates the sun gear reversely.
Therefore, the primary pulley is rotated reversely and the driving force is outputted in the reverse rotating direction.
Scheme 3
| 1 - REVERSE BRAKE (RELEASED) |
|---|
| 2 - FORWARD CLUTCH (RELEASED) |
When the forward clutch and the reverse brake are released, the driving force from the engine runs idly and is not transmitted to the primary pulley.
When the forward clutch and the reverse brake are released, the planetary carrier runs idly and the torque from the tires are not transmitted.
Scheme 4
| 1 - REVERSE BRAKE (RELEASED) |
|---|
| 2 - FORWARD CLUTCH (ENGAGED) |
When the forward clutch is engaged, the driving force from the engine rotates the sun gear normally through the forward clutch.
Therefore, the primary pulley is rotated normally and the driving force is outputted in the normally rotated direction.
Scheme 5
| 1 - PULLEY RATIO LINKAGE | 5 - SECONDARY VALVE |
|---|---|
| 2 - STEPPER MOTOR | 6 - SECONDARY PULLEY |
| 3 - RATIO CONTROL VALVE | 7 - PRIMARY PULLEY |
| 4 - LINE PRESSURE |
When the line pressure circuit is closed by the ratio control valve, the line pressure is not applied to the primary pulley.
When the secondary valve moves downwards, line pressure is applied to the secondary pulley.
Scheme 6
| 1 - PULLEY RATIO LINKAGE | 5 - SECONDARY VALVE |
|---|---|
| 2 - STEPPER MOTOR | 6 - SECONDARY PULLEY |
| 3 - RATIO CONTROL VALVE | 7 - PRIMARY PULLEY |
| 4 - LINE PRESSURE |
The pulley ratio linkage moves to the left direction of the stepper motor. The line pressure circuit opens due to the movement of the ratio control valve which links to the pulley linkage, and line pressure is applied to the primary pulley.
The secondary valve moves to open and fluid in the secondary pulley is drained while maintaining the pulley pressure.
Scheme 7
| 1 - PULLEY RATIO LINKAGE | 5 - SECONDARY VALVE |
|---|---|
| 2 - STEPPER MOTOR | 6 - SECONDARY PULLEY |
| 3 - RATIO CONTROL VALVE | 7 - PRIMARY PULLEY |
| 4 - LINE PRESSURE |
By applying line pressure to the primary pulley, the sliding element moves to the right direction and the steel belt is pushed outward on the primary pulley.
By actuating the "moving-pulley" of the primary pulley to the right direction, the ratio control valve starts to move to the right direction through the pulley ratio linkage which is driven by the sliding element.
By pulling the steel belt to the primary pulley side, the moving-pulley of the secondary pulley moves to the right side also.
Scheme 8
| 1 - PULLEY RATIO LINKAGE | 5 - SECONDARY VALVE |
|---|---|
| 2 - STEPPER MOTOR | 6 - SECONDARY PULLEY |
| 3 - RATIO CONTROL VALVE | 7 - PRIMARY PULLEY |
| 4 - LINE PRESSURE |
Additionally, the sliding element of the primary pulley moves to the right direction and the ratio control valve also moves to the right side and closes the line pressure circuit; this is a completion of the shift.
The secondary valve moves downwards to apply the line pressure to the secondary pulley in order to apply clamping force to the steel belt.
Scheme 9
| 1 - PULLEY RATIO LINKAGE | 5 - SECONDARY VALVE |
|---|---|
| 2 - STEPPER MOTOR | 6 - SECONDARY PULLEY |
| 3 - RATIO CONTROL VALVE | 7 - PRIMARY PULLEY |
| 4 - LINE PRESSURE |
The pulley ratio linkage moves to the right direction in the stepper motor. As the ratio control valve which links to the pulley ratio linkage, moves fluid and the primary pulley is drained.
Because the secondary valve is moving downwards, line pressure is maintained in the secondary pulley.
Scheme 10
| 1 - PULLEY RATIO LINKAGE | 5 - SECONDARY VALVE |
|---|---|
| 2 - STEPPER MOTOR | 6 - SECONDARY PULLEY |
| 3 - RATIO CONTROL VALVE | 7 - PRIMARY PULLEY |
| 4 - LINE PRESSURE |
The stepper motor (2) first moves to the right which causes the ratio valve (3) to vent oil from the primary movable pulley at a speed that allows some belt clamping to be maintained. As the oil is exhausted, the moveable side of the primary pulley moves to the left allowing the belt to be pulled down into the low ratio position by the constantly maintained line pressure in the secondary pulley. As the primary pulley moveable side moves to the left, the ratio valve is pulled to the left which closes off the oil venting from the primary pulley thereby stopping the ratio change. For each position of the stepper motor, there is a corresponding position of the primary moveable sheave therefore.
Scheme 11
| 1 - PULLEY RATIO LINKAGE | 5 - SECONDARY VALVE |
|---|---|
| 2 - STEPPER MOTOR | 6 - SECONDARY PULLEY |
| 3 - RATIO CONTROL VALVE | 7 - PRIMARY PULLEY |
| 4 - LINE PRESSURE |
Additionally, the moving-pulley of the secondary pulley moves to the left direction and the steel belt is pushed outside. In accordance with this, the sliding element of the primary pulley moves to the left side.
The moving-pulley of the primary pulley moves to the right direction, then the ratio control valve also moves to the left direction and closes the drain circuit; this is a completion of the shift.
Scheme 12
| 1 - Line Pressure | 5 - Torque Converter Release Pressure |
|---|---|
| 2 - Forward Clutch Pressure | 6 - Secondary Pressure |
| 3 - Primary Pressure | 7 - Reverse Brake Pressure |
| 4 - Torque Converter Apply Pressure |
| Fluid pressure (minimum - maximum) | Fluid pressure (measurement reference value) | Remarks | ||
|---|---|---|---|---|
| Reference value - Metric / Standard | Measurement condition | Reference value - Metric / Standard | ||
| Line pressure | 0.5 - 6.0 Mpa (5.1- 61.2 kg/cm2) / 73 - 870 psi | Idling | 0.5 - 1.5 Mpa (5.1 - 15.3 kg/cm2) / 73 - 217 psi | |
| Forward clutch pressure | 0.1 - 1.5 Mpa (1.0 - 15.3 kg/cm2) / 14 - 217 psi | Idling (D position) | 0.5 - 1.0 Mpa (5.1 - 10.2 kg/cm2) / 73 - 145 psi | P, R and N positions: 0 Mpa (0 kg/cm2) |
| Primary pressure | 0.1 - 6.0 Mpa (1.0 - 61.2 kg/cm2) / 14 - 870 psi | Idling | 0.1 - 1.5 Mpa (1.0 - 15.3 kg/cm2) / 14 - 217 psi | |
| Torque converter apply pressure | 0.0 - 1.0 Mpa (0.0 - 10.2 kg/cm2) / 0 - 145 psi | Lock-up ON | 0.0 - 0.2 Mpa (0.0 - 2.0 kg/cm2) / 0 - 29 psi | |
| Torque converter release pressure | 0.0 - 1.0 Mpa (0.0 - 10.2 kg/cm2) / 0 - 145 psi | Lock-up OFF | 0.0 - 0.2 Mpa (0.0 - 2.0 kg/cm2) / 0 - 29 psi | |
| Secondary Pressure | 0.1 - 6.0 Mpa (1.0 - 61.2 kg/cm2) / 14 - 870 psi | Idling | 0.1 - 1.5 Mpa (1.0 -15.3 kg/cm2) / 14 - 217 psi | |
| Reverse brake pressure | 0.1 - 1.5 Mpa (1.0 -15.3 kg/cm2) / 14 - 217 psi | Idling (R position) | .5 - 1.0 Mpa (5.1 - 10.2 kg/cm2) / 73 - 145 psi | Out of R position: 0 Mpa (0 kg/cm2) |
OPERATION
| Component | Function |
|---|---|
| Torque converter regulator valve | Optimizes the supply pressure for the torque converter depending on driving conditions. |
| Clutch regulator valve | Adjusts the clutch operating pressure depending on operating conditions. |
| Pressure regulator valve | Optimizes the discharge pressure (line pressure) from the oil pump depending on driving conditions. |
| Shift control valve | Controls flow-in/out of line pressure to/from the primary pulley depending on the stroke difference between the stepping motor and the primary pulley. |
| Lock-up/Select switch solenoid valve | Switches use of the lock-up solenoid control pressure between applying/releasing lock-up and engaging/releasing the forward/reverse clutch (the forward clutch and the reverse brake). |
| Select switch valve | Switches use of the lock-up solenoid control pressure between applying/releasing lock-up and engaging/releasing the forward/reverse clutch (the forward clutch and the reverse brake). |
| Line pressure solenoid valve | Controls the line pressure control valve. |
| Lock-up solenoid valve | Controls the lock-up control valve. |
| Lock-up/Select switch solenoid valve | Controls the select switching valve. |
| Stepping motor | Controls the pulley ratio. |
| Secondary valve | Reduces the line pressure and adjusts the secondary pressure. |
| Select control valve | Engages when making a selection. Adjusts the forward clutch pressure and the reverse brake pressure. |
| Lock-up control valve | Adjusts engaging/releasing pressure for the torque converter. |
| Secondary pressure solenoid valve | Controls flow-in/out of line pressure to/from the secondary pulley depending on driving conditions. |
Outline of the Functions of the Main Components
Scheme 13
Scheme 14
Scheme 15
- Remove the bolts holding the oil pan (1) to the transaxle case. see scheme 306
- Remove the oil pan from the transaxle case.
- Remove the oil pan gasket (1) from the transaxle case. see scheme 307
- Remove the bolts holding the oil strainer (1) to the valve body. see scheme 308
- Remove the oil strainer.
- Remove and discard the oil strainer o-ring.
- Remove the bolts holding the oil strainer bracket (1) to the valve body assembly. see scheme 309
- Remove the oil strainer bracket from the valve body assembly.
- Remove the snap ring (1) from the terminal body (2).
- Remove the nut holding the manual lever (1) to the manual shaft. see scheme 311
- Remove the manual lever from the manual shaft.
- To remove the control valve body assembly on to the transaxle case, fabricate a rod to set the pulley ratio linkage as shown in illustration. (1) 2 mm (0.08 in.) Diameter, (2) 80 mm (3 in.) long, (3) 30 mm (1 in.) long, (4) 50 mm (2 in.) long.
- Install the rod into the linkage stopper hole (5) of the control valve assembly and secure under bolt head (3).
- This sets the pulley ratio linkage (1) in position on the valve body (2). CAUTION: Tilt the valve body assembly away from the transaxle case on the manual shaft side to ease removal. Pay attention to completely remove the terminal body from the transaxle case. NOTE: Mounting bolt (7) is shorter than bolts (1).
- Remove the mounting bolts (1) and (7) of the control valve body assembly.
- Remove the valve body assembly from the transaxle case.
Scheme 16
Scheme 17
Scheme 18
Scheme 19
Scheme 20
- Remove and discard the bushing (1) from the valve body. see scheme 316
- Remove and discard the lip seal (1) from the transaxle case. see scheme 317 CAUTION: Do not drop the pulley ratio linkage.
- Remove the pulley ratio linkage (1) from the valve body. see scheme 318
- Remove the return spring (1) from the valve body. see scheme 319 CAUTION: Do not drop the manual valve.
- Remove the manual valve (1) from the valve body. (Scheme 13)
- Remove the valve body harness (1) from the valve body. (Scheme 14)
- Remove the stepping motor (1) from the valve body. (Scheme 15)