Twice in the last week my car has lost power to the wheels after driving on the highway for around 20 minutes. The engine does not die, but just becomes dissengaged. Each time after i pulled of the highway and shifted gears and operated the clutch, the driveline is engaged again. It is an 87 740 with a 4 speed manual transmission with Overdrive. I'm curious about the clutch which seems a touch out of adjustment or maybe the electronic overdrive doing something funny. I don't recall for sure, but i think i was not in overdrive at least one of the times it happened.