Banging noise in front end

While having a inspection test drive of my 96 P-30 something the tech noted a cracked weld some where on front drivers side frame. I had no banging noise and the tech stated he became aware of this as he noted the windshield wipers cycle a few inches while going across a speed bump at a slow speed. He said the frame weld was causing the wiper linkage to twist a common problem this chassis and he would take care of it during repair of front end. I had the work done at another shop. The tech there said he had never heard of this problem and found no weld problems during inspection.