One problem related to engine shut off without warning has been reported for the 2008 Ford F-350. The most recently reported issues are listed below.
Truck was taken to Ford dealer and diagnosed with low pressure fuel pump and high pressure fuel pump out. Prior to this white smoke rolled out of exhaust while driving on highway and engine shut off. Truck waa towed to dealer with above findings. Ford diesel mechanic stated several issues with high and low pressure fuel pumps on these models. Please look into this. Estimated cost is 13,000 dollars to fix.