Hi I have a 1996 f350 7.3 automatic, a few weeks ago I noticed a faint whining sound almost like a power steering pump whine. The noise only shows it’s ugly face in when the transmission is warm (150-200), in reverse, and if you happen to press the brake or throttle after a certain period of time. Had the transmission checked out since it only has 30,000 miles of daily driving under it. Came back clear supposedly not the tranny.. Eliminated brakes since it will do it without touching them. Only heard in reverse no other gear plus once you get it going to 10-15 mph the noise stops. Really scratching my head on this one.