Certainly the majority of the weight would have been on the rear axle, 8.5 U.S. tons is equal to 17,000 lbs, that is within the normal weight rating for the 2 ton trucks. I imagine that the rating for your truck is in metric tons, I did not research the conversion from metric to U.S. tons. My 2 ton truck is rated at 16,000 lbs GVWR with the standard 4500 lb. front axle. The rear axle on mine is a 15,000 lb unit, GM offered heavier rear axle options.
