Grab the steering shaft as it goes through the bulkhead into the engine bay, and see if there is lots of play, may just be the usual problem of the plastic bush bits worn away, about £3.50 for a new set, easy to do about 20-30 mins.
Also inspect the flexi joint on the drop ink bit from the end of the steering column shaft to the rack itself, concept-racing do these at £35 delivered, very good quality they are, do coloured ones too.
tabetha