Methods and systems for operating a torque converter clutch of an automatic transmission are presented. In one non-limiting example, the torque converter clutch is closed to provide a threshold torque capacity during a vehicle launch. If an engine torque request is less than the threshold torque capacity, the torque converter clutch remains closed.

Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods adjust torque converter clutch opening responsive to whether or not a motor/generator is available to provide a negative torque to a driveline. Further, the motor/generator and the vehicle's engine are operated to provide a desired amount of driveline braking.

In a control apparatus for a vehicle, in the cases where engine torque is higher than first torque and an engine torque change amount is larger than a first torque change amount when control is shifted from complete engagement control of a lock-up clutch to deceleration slip control, an electronic control unit is configured to shift the control from the complete engagement control to acceleration slip control and then shift the control from the acceleration slip control to the deceleration slip control after the vehicle is brought into a driven state.

A lock-up clutch control device that sets a hydraulic pressure command value for a lock-up clutch as a starting device together with a pump impeller coupled to a motor of a vehicle and a turbine runner coupled to an input shaft of a transmission such that an actual rotational speed difference between the motor and the input shaft coincides with a target slip speed that matches a state of the vehicle, and that controls the lock-up clutch based on the hydraulic pressure command value.

A lock-up clutch control device that sets a hydraulic pressure command value for a lock-up clutch as a starting device together with a pump impeller coupled to a motor of a vehicle and a turbine runner coupled to an input shaft of a transmission such that an actual rotational speed difference between the motor and the input shaft coincides with a target slip speed that matches a state of the vehicle, and that controls the lock-up clutch based on the hydraulic pressure command value.

The drive system from the engine (1) to the drive wheels (7) of a vehicle is equipped with a torque converter (2), which has a lock-up clutch (3), and a variator (4). Said engined car is provided with a lock-up control means for controlling the engagement/disengagement of the lock-up clutch (3) and a gear change mode switch-controlling means (FIG. 8) for performing control to switch between a “continuously variable gear change mode” and a “DSTEP gear change mode.” While traveling, the gear change mode switch-controlling means (FIG. 8) prohibits gear change by the “DSTEP gear change mode” when the detected oil temperature is at or below a lock-up engagement-permitting threshold for permitting engagement of the lock-up clutch (3) and allows gear change by the “DSTEP gear change mode” when the detected oil temperature is higher than the lock-up engagement-permitting threshold.

Methods of repairing a torque converter that enable the continued use of a torque converter and result in a repaired torque converter with a higher-strength and more durable construction. In some examples, a backing ring can be replaced with a replacement backing ring that includes a spline ring for replacing the function of a cover spline ring. In some examples, a method of repairing a torque converter can be improved by providing a replacement backing ring with a radial protrusion for locating the backing ring on the cover, and a method of determining an axial location of the radial protrusion.

A control apparatus for a lockup clutch is provided. The control apparatus for the lockup clutch includes an electronic control unit that is configured to: calculate a driven target clutch torque capacity and a driving target clutch torque capacity; set a target clutch torque of the lockup clutch and control the lockup clutch, based on the driven target clutch torque capacity and the driving target clutch torque capacity; and change over the target clutch torque capacity from the driven target clutch torque capacity to the driving target clutch torque capacity when the driven target clutch torque capacity and the driving target clutch torque capacity coincide with each other after an operation state of an accelerator of the vehicle changes over from an accelerator OFF state to an accelerator ON state.

A system for bypassing a torque converter in a powertrain is provided. The system includes a torque generating device including an output shaft and a transmission assembly. The transmission assembly includes a transmission output shaft and a torque converter, a torque converter bypass shaft. The transmission assembly further includes a disconnect clutch selectively coupling the torque converter with the torque generating device and a torque converter clutch selectively coupling the torque converter bypass shaft with the torque generating device. Engaging the disconnect clutch and disengaging the torque converter clutch enables the torque generating device to transmit torque to the transmission output shaft through the torque converter. Engaging the torque converter clutch and disengaging the disconnect clutch enables the torque generating device to transmit torque to the transmission output shaft through the torque converter bypass shaft.

A system for bypassing a torque converter in a powertrain is provided. The system includes a torque generating device including an output shaft and a transmission assembly. The transmission assembly includes a transmission output shaft and a torque converter, a torque converter bypass shaft. The transmission assembly further includes a disconnect clutch selectively coupling the torque converter with the torque generating device and a torque converter clutch selectively coupling the torque converter bypass shaft with the torque generating device. Engaging the disconnect clutch and disengaging the torque converter clutch enables the torque generating device to transmit torque to the transmission output shaft through the torque converter. Engaging the torque converter clutch and disengaging the disconnect clutch enables the torque generating device to transmit torque to the transmission output shaft through the torque converter bypass shaft.