Pressure wash the torsion bar cross mount and the front ant rear torsion bar mounts. Blast away at the accumulation of grime-grease-grit and rust. That will enable you to do a visual inspection. If it passes that, get something like a 1/4 to 3/8 inch diameter punch with a flat on the business end and a hammer and check out the torsion bar cross member by giving it some decent hits every couple of inches.