Help with strange knock???

You added wobble to your description. Jack one side up at a time and have helper rock wheel side to side while you check steering linkages tie rods, idler, etc. for movement. Sometimes a worn component will "hang up" in its worn position at rest. The one wheel on the ground will hold that side steady enough for you to feel any play. Top to bottom to check bearings. Do check your box mounts though as its the last place you had a problem and the loose box might have only been the symptom.