My son and I just replaced both rear trailing arms in his '82 300D with used units from Potomac German Auto. The replacements came with bushings/bearings and emergence brake cables that looked and felt good so we just used them. As posted earlier (doing one side at a time) we jacked the car up, dropped the differential a bit, removed the subframe mounting bolts, and lowered the trailing arm (bottom shock mount had rusted through so shock did not limit downward travel. I left the shock in place until the end to help contain the coil spring should it want to jump out. With the trailing arm down we could lift the spring out by hand. Front trailing arm to subframe bolt was accessbile once the subframe came down in front. Only hitch was a that one of the big subframe bolts was seized in the bushing of the subframe mount. Destroyed the mount getting the bolt out but we replaced them both anyway. Not too bad, just dirty and slow. Should last another 24 years and the car rides a bit higher with the new subframe bushings in place.