Owned the Astro's brother, 2000 GMC Safari AWD ext, drove it for 100k miles. The viscous coupler went bad, and locked it into full time AWD, eventually tearing the front 3rd member mounts out of the frame crossmember. I repaired the crossmember, removed the front driveshaft, and drove it for another couple years, as a replacement viscous coupler was a dealer item only, and cost over 1 thousand dollars at the time. The 4.3 and trans were both bulletproof through 190k miles, no valvejob, no anything. A couple door handles went bad and had to be replaced, and the wire harnesses inside both the front doors went bad, shorting the door locks and electric windows.