You have a serious problem if the tires are only rated for 800lb each. I would be contacting the dealer and get the whole axle/tire situation corrected.
The smallest tire sold for trailers is a 175/80/13 C @1360lbs each.
You coachman should have 14" wheels according to the brochure. The smallest 14" tire will have 1760lbs for load. That's 7,040lbs total. Subtract 10% from the TT GVW and you have 6750lbs on the tires. Under the max load. This is assuming you have 205/75/14C which is the lowest rated 14" tire.
Absolutely no way do you have only 800lbs max load on your tires. Recheck what you have. Post a pic if you can.