A method for operating a drive train, having a main and, an auxiliary drive and a speed modulation gearbox with a fixed mechanical transmission ratio between the two drives, for starting and towing a drive train to a defined set rotational speed. The main drive is started via a direct-on-line-start with direct coupling to a supply network. The auxiliary drive is started simultaneously with at a time before or at a time after the main drive. For towing the drive train to the defined set rotational speed, which corresponds to a defined percentage of a rated rotational speed of the drive train, the main drive is operated motorically in forward mode at least at times and accelerated to its rated rotational speed, wherein parallel to this the auxiliary drive is operated motorically in reverse mode at least at times.

Valve assemblies, clips adapted for use in valve assemblies, and methods of assembling valve assemblies are disclosed herein. A valve assembly includes a solenoid, a valve body, and a clip. The valve body is coupled to the solenoid and extends along a valve body axis. The valve body includes a first inner surface that defines an interior passage, a second inner surface that defines a groove in fluid communication with the interior passage, and a shoulder defined at an interface between the first inner surface and the second inner surface. The clip is coupled to the solenoid and the valve body.

A shift by wire control for a multi-speed vehicle transmission is provided. The control includes a shift by wire shift valve in fluid communication with other shift valves and clutch trim valves to provide double blocking features in the neutral range and a reverse range. The shift by wire valve is configured with multiple differential areas to provide failure modes for all forward ranges.

Valve assemblies, clips adapted for use in valve assemblies, and methods of assembling valve assemblies are disclosed herein. A valve assembly includes a solenoid, a valve body, and a clip. The valve body is coupled to the solenoid and extends along a valve body axis. The valve body includes a first inner surface that defines an interior passage, a second inner surface that defines a groove in fluid communication with the interior passage, and a shoulder defined at an interface between the first inner surface and the second inner surface. The clip is coupled to the solenoid and the valve body.

A method for operating a drive train, having a main and, an auxiliary drive and a speed modulation gearbox with a fixed mechanical transmission ratio between the two drives, for starting and towing a drive train to a defined set rotational speed. The main drive is started via a direct-on-line-start with direct coupling to a supply network. The auxiliary drive is started simultaneously with at a time before or at a time after the main drive. For towing the drive train to the defined set rotational speed, which corresponds to a defined percentage of a rated rotational speed of the drive train, the main drive is operated motorically in forward mode at least at times and accelerated to its rated rotational speed, wherein parallel to this the auxiliary drive is operated motorically in reverse mode at least at times.