Ridding too low
The Minuet 6.0 Metre naturally rides a bit lower than its siblings in the regular Argosy line. It was designed to be towed by what were, at the time, considered compact cars (Chevrolet Nova, Ford Maverick, AMC Pacer, etc. as well as mid-sized cars such as the Dodge Aspen/Plymouth Volare, Chevrolet Malibu Classic, etc.). These coaches provided very little cargo carrying capacity with the OEM axle, so chances are that your axle is worn out or may be seized due to excessive periods of inactivity. To get an idea of how much settling has occurred, park the trailer on a level street or parking lot and then level the trailer and measure the hitch height. I don't have my owner's manual handy, but I believe that the hitch heigh on the Minuet series was 18" -- a quick ckeck of your owner's manual should confirm this fact.
Even with a good axle the clearance is going to be tight unless a new axle is purchased with the maximum departure/down angle which I believe is 32 degrees. The axle on my Minuet was ordered with the OEM settings and I only gained about 1.5" of clearance with the new axle. I still must carefully watch driveways and almost always approach at a sharp angle to lessen the chance of dragging the rear bumper and dump valve apparatus. The factory frame extensions below the bumper on my coach aren't quite deep enough to adequately protect the dump valve mechanism -- I have had to have this apparatus repaired three times in the six years that I have owned the coach.
Good luck with your investigation!
P.S.: The factory suggests that drag wheels on the rear bumper should not be used on Airstream or Argosy trailers as they tend to place pressures on the frame for which it wasn't designed. The extra steel member on the bottom of the bumper extension is considered a "sacrificial" skid plate.
Kevin D. Allen
WBCCI (Lifetime Member)/VAC/Free Wheelers #6359
1964 Overlander International/1999 GMC K2500 Suburban (7400 VORTEC/4.11 Differentials)
1978 Argosy Minuet 6.0 Metre/1975 Cadillac Eldorado Convertible (8.2 Liter V8/2.70 Final Drive)