Just discovered a second shock failure on the '39. Left shock has failed twice! Rear suspension is 4 bar/panhard bar with air bags. Detach the bags and shocks and the rear moves up and down smooth. Shocks are Monroe 32275 with a range of 10.5 to 15.5 inches. Ride height is about 13" depending on air pressure. Shocks are for a 2000 Ford Windstar with a rear weight rating of 2800 lbs. rear of the '39 comes in at 1750lbs. When I took the shock out there was NO resistance removing the bolt. That tells me there is no mis-alignment side to side. I can see one faulty shock but not two on the same side. Any ideas what will cause a shock to fail?