The rear shocks are rebuildable.... Are you setting your pressures while on the center stand? I really didn't believe in the auto leveling.....couldn't find a road that was flat or smooth enough to actually work correctly.
The best way is to put the bike on the center stand.....use the Up and Down switches to set the pressures....It will take a little time of getting it to the way you like it by riding the bike after setting the pressure. But that was my excuse to get to ride when I was working on the bike!
I ran about 45lbs in the rears and 3 in the front for solo riding and 65lbs inthe rearand 5lbs in thefront for 2up riding. That was formy 85 LTD.....your poundage may vary as the Aspencades and Interstates couldn't run as high of pressures in the rear as the LTD could.
EDIT:.....Oh I see you have a LTD....so your max pressures are 14lbs in front and 92lbs in rear. All pressures are set with the bike on the center stand.