As for your vehicle dragging ass...your rear air springs are shot. You can get replacements from an importer in Durban, I'll get their details for you in the morning. Easy fix and actually a "fun" first project to tackle if you have an hour to spare and a few simple garage tools like a jack and sturdy tripods. Have a look on Arnotts.Com for a video on how to do it. It cost me R4800 for both springs. It only gets expensive if your compressor motor has seized from continual operation as a result of a badly torn airspring. Holding thumbs that's not the case. If you do find yourself in that position then at least you know the same crowd who import the springs also import the compressors at a reasonable price...I'd first attempt a rebuild if it was mine though because there isn't much to them. Bearing man will likely have everything you need to get it going again.
The workshop manual unfortunately doesn't exist and I go online when I need pages from the service manual...frustrating but it gets the job done.

Good luck.