general problems of the 2003 Ford E-450

2003 Ford e450 drivers side rear wheel came off while driving on the ohio turnpike. The rim had wear marks where the lug nuts wore large holes, which caused the studs to snap off. Ohio traffic crash report #10-0038-91 updated letter 04/29/10.

I have a jayco motorhome on a Ford e450 chassis, original. Tires michelin 225/75 with load factor e. Max load of the tires is 9880lbs, my actual rear axle weight 9270 (static and motorhome empty with no water, fuel tank 1/3 full) according to michelin that is asking for tire failure ( had 2 already) because the dynamic loads (going down the street, bumps - uphill - downhill- sideloads) will be over the tire limit. That's the reason the law requires pass, cars and light trucks to have a 16% reserve capacity; mine is down to about 2%. With full fuel and water tank, little bit of staff loaded for vacation or putting anything on the trailer hitch (boat or even loaded bike rack) I am overweight for the existing tires and max rear axle weight I know that is not an issue Ford has to deal but jayco. But I would very much appreciate your expertise about what to do (is that motorhome a risk to drive , maybe unsafe?) is there any means to increase the max rear axle weight on that e450 chassis? any way I could put on a different tire size (enough room on the rim / wheel-well;that would increase the max tire load about 1000lbs - but is that legal and doable, especially. With the dual tires. I am looking forward to your answer.