Hi, I have a 2001 F350 Super Duty 7.3 L Diesel, extended cab 4X4. I have owned this truck since new. It currently has 145,000 miles on it. This past spring I replaced both front wheel bearings, hubs, ball joints, seals. Today when I locked the hubs (manual hubs) the front end shutters extremely bad in and out of 4 wheel. I played with the lock outs and finally found that it is the lft side causing the problem. I also replaced the stock locks with aftermarket locks at arouns 50,000 miles. Any suggestions??/
Thanks

 

Have you checked your axle u-joints? Also when you replace the hubs thereare shims and a clip where the axle comes into the hub to properly hold the axle shaft in the correct position.