whats causing this

Wow…you certainly do. You need to stop driving the car immediately; it's really unsafe in that condition. Your pitman and idler arms are loose on their mountings, as it seems. Your centre link may well be loose at one or both ends where it attaches to the pitman (driver's side) and idler (passenger side) arms. There may also be wear and/or looseness in other components such as the tie rod ends, control arm bushings, and strut rod bushings. You need to have a good, qualified shop do a careful inspection of the entire front end. You may be lucky and wind up getting away with just tightening the loose nuts, but don't count on it; you are likely looking at replacing parts. Be prepared for collateral damage if the car has been driven over a long distance and/or time with this looseness; the parts are not meant to rock and slam against each other as happens when they're loose.