Abstract: Embodiments of the present invention provide a vehicle drivetrain assembly operable in a first mode and a second mode. The vehicle drivetrain assembly comprises: a drive unit arranged to generate power to drive a vehicle (1); an automatic transmission comprising a torque converter and operatively coupled to the drive unit to receive the power; and a control system comprising one or more controllers (11), the control system being arranged to adjustably limit the maximum torque delivered to the transmission from the drive unit. When the automatic transmission is in first gear with the torque converter stalled, the control system limits the maximum torque to a first level when the vehicle drivetrain assembly is in the first mode and to a second level when the vehicle drivetrain assembly is in the second mode, the first level being lower than the second level.

Abstract: A vehicle wheel assembly (1) for supplying compressed air from a vehicle axle to a tyre (3) comprises a vehicle wheel (5) and a control valve assembly (7). The wheel (5) comprises a wheel hub (9) for mounting the wheel (5) to a vehicle (V); and a wheel rim for mounting a tyre (3) on the wheel (5). A transfer line (19) is provided in the wheel for transferring compressed air from the wheel hub to the wheel rim (11) for inflating the tyre (3). The control valve assembly (7) comprises an inlet, an outlet and a control valve (25) operably located between the inlet and the outlet for controlling passage of compressed air between the inlet and the outlet. The control valve assembly (7) is removably disposed in the wheel hub (9) such that fluid communication is established between the control valve assembly (7) and the transfer line (19).