Underbody Shield problems of the 2003 Chevrolet Avalanche

Failure of front cross member beam, excessive noise(popping and grinding)and premature wear. Failure occured at 25000 miles. Per Chevrolet, the perscribed fix is to install hardened washers and grind and polish friction points. This has been done, yet problem continues. Dealer has told me this is common to the vehicle in question but they can do no more as Chevrolet does not have a solution to the problem.