Most likely, the Nitrogen accumulators need replacement. As for wear items, I would replace the bushings on top of the strut towers and the spring shims. If the sagging is different from side-to-side, I would inspect the leveling valve and the springs. Finally, if there is general slop in the rear, the subframe mount bushings could be replaced. Hope this helps, Andrew Seidel.

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86 560SEC
85 500SEC Lorinser
83 300D Turbo
75 240D