Sway Block - RH Fits Allis Chalmers 175 185 170 180 70242320One New Aftermarket Replacement Right Hand Sway Block Fits Allis Chalmers Tractors This Right Hand (RH) Category II sway block is part of the 3 point hitch system on Fits Allis Chalmers 100 series tractors. Sway blocks control lateral movement of the lower hitch arms, preventing implement swing during transport and field operation. This is the right hand block only verify you need RH before ordering, as the left hand block is a separate part.