Method of exchanging a rack of a rack and pinion drive arrangement and jig assembly

A method of exchanging a rack of a rack and pinion drive arrangement, which arrangement comprises a first toothed rack and a gearbox comprising a plurality of pinions which are arranged to mesh with the first rack which pinions are connected to a respective primary gear via a rotational compliance device, which method comprises;

• providing a rack and pinion drive arrangement with a first rack installed in meshing engagement with the pinions of the gearbox,
• providing a jig assembly comprising a second toothed rack and a coupling arrangement,
• arranging the second rack in longitudinal coaxial alignment with the first rack,
• connecting a first end of the second rack to a proximal end of the first rack via the coupling arrangement,
• bringing the second rack into meshing engagement with the pinions of the gearbox by linear displacement of the first and second rack, and
• disconnecting the first rack from the second rack, which method further comprises;
• calibrating the nominal rotational position between each pinion and primary gear when the first or the second rack is in meshing engagement with the pinions of the gearbox.