Automatic Transmission: Specifications Suzuki Forenza I

Torque Converter

The converter consists of the impeller, the turbine wheel, the reaction member (stator) and the oil to transmit torque. The impeller, which is driven by the engine, causes the oil in the converter to flow in a circular pattern. This oil flow meets the turbine wheel, where is direction of flow is deflected. At the hub, the oil leaves the turbine and reaches the reaction member (stator), where it is once again deflected so that it reaches the impeller at the correct angle of flow.

The reversal effect generates movement in the stator, the reaction torque then amplifies the turbine torque.

The ratio between turbine torque and torque is referred to as torque multiplication.

The greater the difference is speed between the pump and turbine, the greater the torque multiplication; it is at its highest when the turbine is at a standstill. The higher the speed of the turbine, the lower the torque multiplication.

When the turbine speed reaches about 85% of the pump speed, torque multiplication = 1, i.e. the turbine torque equivalent to pump torque.

The stator, which bears against the housing via the freewheel, is then rotating freely in the oil flow and the freewheel is over-come. From this point onwards, the converter acts as a straightforward fluid coupling.

Space Behind Lock-up Clutch Piston

Scheme 1

Torque Converter Lock-up Clutch (TCC)

The converter lock-up clutch is a device, which eliminates converter slip and thus helps to improve fuel consumption.

The previous control principle for converter lock-up clutch operation has been replaced by a controlling function on the 4 HP 16. The converter lock-up clutch is engaged and released in a controlled manner. During the controlled phase, a slight speed difference between the impeller and turbine wheel is established. This ensures that the engine's rotating vibration is not phased on to the transaxle. The result is optimum shift quality.

An electronic pressure-regulating valve determines pressure regulation of the lock-up converter clutch's piston.

When open (conversion range), the oil pressure behind the converter lock-up clutch piston and in the turbine zone is equal. The direction of flow is through the turbine shaft and through the space behind the piston, to the turbine chamber.

Scheme 2

To engage the lock-up clutch, the direction of flow is modified (reversed) via a valve in the hydraulic selector unit. At the same time, the space behind the lock-up clutch piston is vented. The oil pressure passes from the turbine chamber to the lock-up clutch piston and presses it against the converter's cover. The turbine is thus blocked by way of the linings between the piston and cover, and permits rigid through drive with no slip (or reduced slip if controlled) to the mechanical stage of the transaxle.

Scheme 3

Torque Converter Lock-Up Clutch (TCC) Diagnosis

To properly diagnosis the lock-up clutch (TCC) system, perform all electrical testing first and then the hydraulic testing.

The TCC is applied by fluid pressure which is controlled by a solenoid located inside the valve body. The solenoid is energized by completing an electrical circuit through a combination of switches and sensors.

Torque Converter Stator

The torque converter stator roller clutch can have one of two different type malfunctions

1. Stator assembly freewheels in both directions.
2. Stator assembly remains Locked up at all times.

1. Condition A - Poor Acceleration Low Speed The car tends to have poor acceleration from a stand still. At speeds above 50 - 55 km/h (30 - 35 mph), the car may act normal. If poor acceleration is noted, it should first be determined that the exhaust system is not blocked, and the transaxle is in 1st (First) gear when starting out. If the engine freely accelerates to high RPM in N (Neutral), it can be assumed that the engine and exhaust system are normal. Checking for poor performance in "Drive" and "Reverse" will help determine if the stator is freewheeling at all times.
2. Condition B- Poor Acceleration High Speed Engine RPM and car speed limited or restricted at high speeds. Performance when accelerating from a standstill is normal. Engine may overheat. Visual examination of the converter may reveal a blue color from overheating. If the converter has been removed, the stator roller clutch can be checked by inserting two fingers into the splined inner race of the roller clutch and trying to turn freely clockwise, but not turn or be very difficult to turn counter clockwise.

General Specifications

GENERAL SPECIFICATIONS

Fluid Capacity

FLUID CAPACITY CHART

Line Pressure Specification

LINE PRESSURE SPECIFICATION

Tightening Torque Specifications

TIGHTENING TORQUE SPECIFICATIONS

See also:
• ON-BOARD DIAGNOSTIC (OBD II) SYSTEM CHECK