2005 F-250 4x4 6.0 PSD. Hit 15k. Service manual says I should lube steering, suspension, propeler shaft and such. So I get the grease gun out, and find no grease fittings? I found one grease fitting where the front axel conects to the fron hub/wheel. Is this the propeller shaft? Kind of looks like a propeller! Where are the rest of the grease fittings? Are the covered with dust covers or something?