solved: rear vibration...Now did the outside rear tires get overloaded?
FOT sent me to Stewart and Stevenson Longview, TX for the rear vibration...It was due to a worn u joint and a loose nut on the P-3 Carrier. They removed the drive shaft and rear yoke and dampener assembly. The lock nut and rear bearing were removed to evaluate the bearings and races (which were good). They reassembled and torqued the nut and set the lock nut flange; installed the new rear seal and u-joints; and reinstalled the drive shaft and lubed. A road test was done by me with the tech on board.
To get to the transmission, they lifted the motorhome with four lifts that raised each tire position simultaneously. Each lift was rated at 30,000 lbs. and located at each wheel position. Unfortunately, only the outside rear tires were lifted and only they bore the weight usually divided by the duals.
Many years ago when we were loaded to near capacity, RVSEF weighed us. Then each rear tire position, rated for 5305 X 2 lbs., carried about 9400 lbs each (rear axle carried 18900 lbs). We now travel a little lighter and I'd assume around 18,000 lbs on the rear axle. So around 9000 lbs was loaded on each 5305 lb rated outside rear tire for 6 hours. Do I now have tire problem? We have subsequently driven 660 miles from Longview to Mission, TX with no vibration or tire failure.
Bob