A couple of years ago, I was traveling with my F-53 Chassis, class A Motor Home when I notice the smell of gear oil. Checked the rear axle and the inside of both inner rear rims were covered in gear ...
1500 bucks. I do mine in the driveway. 30 bucks a side for the seals but you need a good torque wrench that indicates both clockwise and counter clockwise plus the special socket to remove the hubs....and gear oil, almost forgot that.
Ford isn't the only one who uses a rubber hose, they all do.