Yes I did it, 2015 F-150 and 35 foot TT

Samsonsworld wrote:
Usually a shaft breaks when the wheel is spinning and comes to a sudden stop. Only times I've seen it were in an accident or offroading. I've seen trailer bearing burn up...but never on a vehicle.

If you want to believe that $1700 gets you shocks, springs, wheels, e rated tires AND a thicker frame, better cooling system, a hd transmission and a beefed up axle shaft designed in area 51 using alien intelligence, more power to you.

I only disagree with your position that the 7 lug axle existed for marketing only. Marketing doesn't get to spec parts on a truck, it's simply a NPD/R&D/Engineering role. I agree with the fact that the 9.75 axle is a tough lil bugger, and Ford (nor any other manufacturer) is suffering from more than a very rare axle failure. And some of these trucks get extremely overloaded and still don't experience failures.

A little history may help:
97-99 Light Duty F-250 (which became the 00-03 7700 F-150, which then became the HD payload pkg w/8,200 GVWR) the 10.25 7-lug Sterling axle came standard. In 2005, the 9.75 axle was rated at 4200 lbs., the 10.25 was rated at 5300 lbs. In 2009, the 10.25 axle was dropped and the 9.75 axle became the standard, albeit with 7 lugs for the HD package. After discontinuing the 10.25 axle, Ford spec'd a 9.75 axle with 7 lugs, rather than fitting the 6-lug 9.75 axle they already had off the shelf. I doubt this was to sell trucks, for an option that had less than a 1% 'take' rate. Just simply wouldn't pay for itself with those extremely low production numbers.