A limited-slip driveline apparatus comprising: a first driveline component (102, 104) that is rotatable relative to a second driveline component; a clutch configured to resist relative rotation between the first driveline component (102, 104) and the second driveline component at least when the clutch is actuated; an actuation arrangement for actuating the clutch, the actuation arrangement including: a hydraulic pump that pumps hydraulic fluid through a hydraulic circuit when relative rotation exists between the first and second driveline components (102, 104, 22), wherein hydraulic pressure generated by the hydraulic pump within the hydraulic circuit 34) is used to actuate the clutch; and a flow regulating valve for regulating a hydraulic fluid flow rate through the hydraulic circuit to prevent the hydraulic fluid flow rate from exceeding a set maximum flow rate regardless of a magnitude of the hydraulic pressure in the hydraulic circuit characterized in that the flow regulating valve has an outer body which forms a valve sleeve, wherein a valve piston is received within the valve sleeve, the valve sleeve defining at least one outlet opening and the valve piston defining a plurality of outlet openings positioned at an intermediate location along the valve piston, the at least one outlet opening of the valve sleeve and the at least one outlet opening of the valve piston cooperating to define a variable outlet orifice for regulating a hydraulic fluid flow rate through the hydraulic circuit, the flow regulating valve being configured to reduce the size of the variable outlet orifice of the flow regulating valve to prevent the hydraulic fluid flow rate from exceeding the set maximum flow rate regardless of a magnitude of the hydraulic pressure in the hydraulic circuit. a first driveline component (102, 104) that is rotatable relative to a second driveline component; a clutch configured to resist relative rotation between the first driveline component (102, 104) and the second driveline component at least when the clutch is actuated; an actuation arrangement for actuating the clutch, the actuation arrangement including: a hydraulic pump that pumps hydraulic fluid through a hydraulic circuit when relative rotation exists between the first and second driveline components (102, 104, 22), wherein hydraulic pressure generated by the hydraulic pump within the hydraulic circuit 34) is used to actuate the clutch; and a flow regulating valve for regulating a hydraulic fluid flow rate through the hydraulic circuit to prevent the hydraulic fluid flow rate from exceeding a set maximum flow rate regardless of a magnitude of the hydraulic pressure in the hydraulic circuit a hydraulic pump that pumps hydraulic fluid through a hydraulic circuit when relative rotation exists between the first and second driveline components (102, 104, 22), wherein hydraulic pressure generated by the hydraulic pump within the hydraulic circuit 34) is used to actuate the clutch; and a flow regulating valve for regulating a hydraulic fluid flow rate through the hydraulic circuit to prevent the hydraulic fluid flow rate from exceeding a set maximum flow rate regardless of a magnitude of the hydraulic pressure in the hydraulic circuit characterized in that the flow regulating valve has an outer body which forms a valve sleeve, wherein a valve piston is received within the valve sleeve, the valve sleeve defining at least one outlet opening and the valve piston defining a plurality of outlet openings positioned at an intermediate location along the valve piston, the at least one outlet opening of the valve sleeve and the at least one outlet opening of the valve piston cooperating to define a variable outlet orifice for regulating a hydraulic fluid flow rate through the hydraulic circuit, the flow regulating valve being configured to reduce the size of the variable outlet orifice of the flow regulating valve to prevent the hydraulic fluid flow rate from exceeding the set maximum flow rate regardless of a magnitude of the hydraulic pressure in the hydraulic circuit.