It is hard to give a completely accurate diagnostic on a suspension noise from here
. I have just today finished a suspension rebuild on a 1989 300SE. I replaced all the suspension components that the rubber boots were torn up on. That did include item 20. I would recommend as a minimum item 20 and the lower ball joints. Again, perform a thorough visual inspection of the boots. If there is any doubt then replace them. Look real good at all the bushings and replaced what is dried up/cracked and busted up looking. I wish I had photographed the way I change them without compressing the spring. I use a "come a long" fastened to another cars tow hitch (I have it parked in front of the car I am working on) and pull the lower control arm forward with the come along. Works like a charm. I totally remove the fasteners holding the back plate and use the track rod adjustment to help drive the track rod mount out. Use it to help pull the new one in too. Works like a charm
Sorry, I can't say for certain this will work on your model. Send us a pic of it and we will advise as able.