Carrier/rack problems of the 2001 GMC Yukon

On a recent trip to canada it was found that four(4) of the welds holding the square receiver to the horizontal member were cracked, one weld was ok. Not being satisifed with the weight distribution performance of the hitch I had contacted can-am RV center (towing specalists) in ontario canada to check the hitch while I was up there. When raising the vehicle on the lift they found four cracked welds which they repaired and attached some additional members to the frame in order to transfer more weight to the front axle. Prior to this modification I was reducing the front axle load by 600#, which made the front end of the vehicle light. I believe this receiver is over rated and very dangerous. This factory receiver is rated at 12000# trailer weight and 1500# tongue weight which I believe to be over rated. It also does not transfer the weight evenly over the vehicle as it should. I am towing a 9000# trailer with a hitch weight of 1200#. It appears that the gm priorty is selling Yukon's and including a receiver from the lowest bidder. As of this date I have been told by gm that they not reimburse me for the weld fix($70) because it was not done by a gm dealer. If someone drops a $40,000 trailer on the interstate it will cost gm more than $70. Good luck and thanks, lloyd badman.