It seems like a bearing of the steering rack pinion has broken (usually the lower one,it is a ball bearing).It has happened to me again. The rack is cheap to rebuild (two bearings,two gaiters and the plastic bush on the rack end opposite the pinion).If you can find the bush,go for it and you will have a new rack.Otherwise if you can find a cheap and good s/h rack,all is OK. Check also the steering column universal joint, if your car is of the later type.