[GRutter]

A vehicle with proper caster and toe-in should not shimmy, if other steering components are in good condition.

When you have shimmy problems or "the death wobble", there are always a multitude of steering components to evaluate... worn king pins, brakes dragging, toe-in not set correctly, worn wishbone, wheel bearings etc.

You should be able to totally disconnect the drag link and the car should want to run straight, without shimmy (just hypothetically speaking.... please do not try this).

As long as spring tension is maintained on the steering balls, it should not be a factor in wheel shimmy.. It might contribute to harder steering during turning, but not shimmy.