The E450 chassis under our Class C is a "2005" chassis. The cutaway E450 chassis was built by Ford in Sept/Oct of 2004. Itasca calls the coach a "2005" coach.
The transmission it came with was a 5R110 5-speed (6 speeds internally) with Tow/Haul mode via a switch on the gearshift lever.
Our E450's orginal 5R110 transmission blew at around 61,000 miles. On RV trips we climb long highway grades at any speed we want at any outside summer temperature. Our Class C weighs around only 11,800 lbs., or slightly more, when loaded for travel. One of the reasons we shopped for a 24 foot Class C built on an over-kill E450 chassis was so that we could drive this way (we do not tow) whenever we wanted.
I had a remanufactured 5R110 transmission - supposedly with "heavy duty" options - installed instead of having the original transmission rebuilt. I hope that there is such a thing as a heavy duty way to rebuild the 5R110 5-speed transmission and that we actually wound up with it after dropping $5600.
I can't imagine how the Ford 5-speed transmission can be over-heated pulling only around 11,800 lbs. of motorhome. It seems to me that we shouldn't have to be concerned with over-heating our transmission under these conditions. Are those transmission fluid heat charts above really serious -> one has to keep transmission temperatures way down to 185 degrees or less for 100,000+ mile transmission life??? You could of fooled me!!
