My buddy and I are working on a '82 300TD that he just picked up that has around 296K on the dial. Driving it around, we noticed the squatty rear end and the swaying going around corners. The resorvoir is full of fluid for the SLS. I've done a cursory search and found the basic layout of the system with the pump, valve attached to the torsion bars, accumulators, and spheres (shocks). I know that the two basic things to check is to disconnect the valve arm from the torsion bar and move it independently to see if the rear will raise and lower. The other is to check for oil on the shock rods. Any other advice? Are these systems as straightforward as they seem?

This might help you diagnose your wagon rear a little.
Diagnosing your Self-Leveling-System: by yours truely

It's a write-up I did after trying to chase down some noise in the rear of my wagon. It ended up being the sway bar links, but none the less I thought I would write-up all the stuff I found to help others troubleshooting their SLS.

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