I have a 2007 w/ automatic trans. and 7,500 miles on it. I bought it for my business and I haul a 65 gallon water tank inside. The other day I filled the tank, and added other gear that weighed maybe another 50 pounds and tried it out. While on a logging road traveling maybe 5mph or less, the rear suspension will bottom when hitting a 4-6 inch pothole! Funny thing is when unloaded, hitting the same potholes, it feels like the suspension is rock hard. What gives(no pun intended)? How can I improve the unloaded ride and not bottom when loaded?! Any info would be appreciated!