Sherical ball joint breakage is a problem on our 500 series flex. We cut off the remants of the thread on a broken ball close to ball socket, then carefully weld the head of a good grade 5_8 UNF bolt onto the ball joint socket using the high grade "weld all metals" type rod and reinstall. Seems stronger than the original as it gets rid of the weak point and costs a fraction of the same. We and others here, also have problems with the skid plates locking up over centre when pushed right to their upper limit travel. Have not satisfactorily solved that one yet, but initial tries show that two lengths of light flat spring steel, bolted onto the back of the skid plates each side of the front elevator and extending back under the front's rear frame member to give a positive down pressure on the rear of the skid plates, seems to promise a solution.
