Flrice, Since your using clamp-on duals in mud I'm assuming you have the 30.5's dished out for clearance. This puts the center of the load way too far out, causing a huge moment on the rim flange and final drive. If you keep that setup I think you'll just keep breaking stuff. The cheapest way to correct this is to buy the frame extensions with the truss rod that will move the final drives out and let you flip the 30.5's around. This will releive a lot of stress if you have a substantial amount of offset in the inner rim. An even better solution would be cut the flange out of the 30.5 rim and weld in a heavier flange with more offset. Try to end up with the flange centered between the outside of the two tires to minimize the moment and therefore minimize the stress. You may need longer studs (or boltsIJ) if you go with a lot thicker flange. PS: Wold Rim and Wheels will sell you the frame extensions in standard or custom lengths and could probably give you some good advice. The number is 1-800-443-9653.