It's easy to see all the rear suspension links if you jack up the rear and pull the wheels off.
The "links" are actually heavy gauge steel stampings with a steel sleeve vulcanized into a bushing on each end (except the tie rod, which has a cylindrical bushing on the inner end and a tie rod end on the outer). Only the tie rod is adjustable, the others are all fixed length.
The rubber gets displaced with age -- tends to get thinner on the side where the pressure is -- and will eventually wear out, leaving the links "loose". This allows all sorts of motion to show up at the wheel carrier (the part the wheel bolts to), and funny steering.
Does the rear feel "tight" while driving, or does it feel like the body is moving slightly on the frame when you make turns? If it feels sloppy, for sure you have some tired links.
The Spring link, the one on the bottom, has a rubber bushing on both ends.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!