Bobbo wrote:
I have a friend who is a retired RV salesman. That is what he did all his life. He towed a medium/large fiver with his F-250 for years before deciding to go out west. Driving through the Rocky Mountains, he went up a medium grade, crested the top, and went down a steep grade into the valley. When he tried to make it up the steep grade on the other side, the truck couldn't pull the fiver. He turned around to go back to find another route, and the truck couldn't pull the grade the other way either. He ended up having to trade his truck for a bigger truck to get his fiver out of the valley.
Moral of this story, don't use trust a marginal set-up.
For a few hundred $$ a new ring gear would have gotten him over that hill with no worry.
I think he just wanted a new truck.