Check steering idler for Vertical play. Play is bad. Must be solid.
Easy to do. Pas side front wheel. Hold at 3 and 9 o'clock, and wiggle in and out on the steering axis as if checking a wheel bearing for play. But as you do so, watch the steering idler forward joint through the rear if the wheel arch. Give it loads of welly, no need to jack the car. If there is play that joint will move up and down, allowing the pas side road wheel to move independently of the rest of the steering and the drivers side wheel.
If ok, then double check rearward wishbone bushes. The symptoms you describe sound like play between the two parallel lines(very simplistic description) of the steering linkage and or the wishbones and subframe.
Wishbones and subframe do the suspension, steering linkage does the sterring obviously. To work correctly they must move without play in a parallelogram pivoting type motion, or the steering will almost do what it wants.
Something is not tight with those linkages or bushes somewhere. Your mission is to find it.
