After towing my fifth wheel (13000lbs) 175 miles up and down hill in Washington yesterday, I notices a smell like hot brake linings when I parked the truck and trailer. Wasn't the brakes, they were cool. Could it be clutch? Truck has 19000 miles, mostly all pulling trailer. Noticed the smell when we got to the campground last Saturday and then again when we got back yesterday. Anyone else experienced this?