The CAT actual numbers: Steer Axle 4620
                                                  Drive Axle 9980
                              GAWR        Front 4600
                                                  Rear 9460
The other question I had is.... My rear tires are rated@ single 2680lbs or dual 2470. I assume since the rear axle is dual,  the total weight the tires could Carrie would be 2470 X 4 or 9880lbs.  
So not only was the back axle overloaded,  so were the rear tires.  
A dealer I spoke with once while looking at a travel trailer suggested you should stay at 80% of Max weight.  I can't see how this would be possible unless the kids and the dog stayed home.