FORD 2013 F-550 v.1 - Manual (Page 382)

On vehicles equipped with dual rear wheels, retighten the wheel lug nuts
to the specified torque at 100 miles (160 kilometers), and again at
500 miles (800 kilometers) of new vehicle operation and after any wheel
disturbance (such as tire rotation, changing a flat tire, wheel removal).
Bolt size Wheel lug nut torque*
ft-lb N
•m
M14 x 1.5 165 224
* Torque specifications are for nut and bolt threads free of dirt and
rust. Use only Ford recommended replacement fasteners.
It is important to follow the proper wheel mounting and lug nut torque
procedures.
On all two-piece flat wheel nuts, apply one drop of motor oil
between the flat washer and the nut.
Inspect the wheel pilot hole and
mounting surface prior to
installation. Remove any visible
corrosion or loose particles.
Wheels and Tires 381
2013 F-250/350/450/550 (f23)
Owners Guide gf, 1st Printing
USA (fus)