Torsion bar assembly and method of assembling same

A torsion bar assembly comprising:

• an input shaft;
• an output shaft;
• a torsion bar that connects the input shaft to the output shaft and fixes a relative angular position of the input shaft and output shaft at a neutral position when no torque is carried by the torsion bar;
• at least one end stop face on the input shaft that co-operates with a respective end stop face of the output shaft to limit an angular deflection of the torsion bar assembly in a first direction away from the neutral position;
• at least one end stop face on the input shaft that co-operates with a respective end stop face of the output shaft to limit an angular deflection of the torsion bar assembly in a second direction that opposes the first direction;
• a first alignment feature provided at or close to an end of the input shaft nearest the output shaft and a second alignment feature provided at or close to an end of the output shaft nearest to the input shaft, the first alignment feature facing the second alignment feature across a gap so that the first and second alignment features do not contact each other over a range of angular movement of the torsion bar, the first and second alignment features each defining respective contact surfaces that are located such that if the input shaft and the output shaft are pressed axially towards each other to close up the gap the contact surfaces co-operate to set relative angular positions of the input shaft and the output shaft to correspond to the neutral position and to further prevent relative angular movement between the input shaft and the output shaft.