Scary Handling Problem

Thanks for all the responses. PLEASE keep the ideas coming. We are towing 4 down, steering wheel is not locked, xfer case in neutral and tranny in park. Had the tires rotated on the Winnie a while back and told them to air them up, but haven't checked them, so that's a possibility. Guess we also need to look into getting the Winnie aligned. The tow bar is not level, looks like a 2 inch drop from the MH to the toad. We tie a white cloth in the center of the steering wheel on the Jeep when we are towing so we can make sure the wheels are turning freely. Haven't tried the square on the receiver, but when we get home from our current trip, will check it out. Right now, if the problem gets too bad, we disconnect the Jeep and run them separately. WHAT A PAIN!! Ron, don't think we have any EXPERTS in our area of the country. Sure wish we did.