PMcD-
According to the brochure for your coach (link
here), Winnebago offered the 36M on two different Workhorse chassis:
Chassis C:
Tires: 19.5 inches
GVWR: 20,700 pounds
GCWR: 26,000 pounds
Chassis E:
Tires: 22.5 inches
GVWR: 22,000 pounds
GCWR: 26,000 pounds
For both chassis, the hitch info is: "5,000-lbs. drawbar/500-lbs maximum vertical tongue weight"
For flat towing, the rule is GCWR minus coach weight or the "drawbar" weight, whichever is lower. If the coach is loaded to the max weight, then Chassis C's flat towing limit would be 5,000 pounds (hitch rating), and for Chassis E would be 4,000 pounds (26,000 - 22,000 = 4,000).
For towing a trailer, 5,000 pounds horizontal and 500 pounds vertical (tongue weight). If you use the rule-of-thumb that tongue weight should be 15 percent of the loaded trailer weight, then the loaded trailer weight must be 3,333 pounds (500/0.15 = 3,333).
Your coach should have a label somewhere inside that lists the values for your coach as it came from the factory. Look for it inside a cabinet door or on the wall near the driver's seat. Please confirm the numbers for yourself; my words (above) could be in error!