i have a 2005 f-250 superduty 6.0L with the torqshift trans. Just lately it started to shutter for a few sec. when put in reverse. Also a couple of weeks ago while i was pulling a load it would not upshift and the tow/haul light started flashing, so i shut her off and restarted and it worked fine. I was hauling again this weekend and the truck worked great but the tow light flashed most of the time, and now i have this shutter when i put it in reverse. Could this be an eletronic problem or internal?