One problem related to crankcase (pcv) has been reported for the 2008 Ford F-350. The most recently reported issues are listed below.
Upon returning from a short drive I noticed oil on the ground. . . Had truck towed to local Ford dealer . . . When inspected I was informed the self cleaning exhaust system caused the rings to wear prematurely and build pressure in the crankcase causing oil to spew out any opening ie the dipstick tube. A diesel engine should have been expected to last 2-3 times the 165,000 miles on the truck.