Sound like a guide rod bushing. Pretty simple fix on the W126 chassis.

With the car off the ground grab the front wheel at 9 and 3 O'clock and pull forward/rearward. Look for movement in the rod that extends to the large bushing in the aluminum casting.

The casting can be removed by removing the three bolts per side on the rear cross brace, then remove the three large casting bolts. Loosen the clamp on the rod and count the number of turn it takes to get it loose from the bushing. Install the new one the same number of turns to get the alignment close.

With the casting off you remove the bushings rear cover (four allen bolts) then drive the bushing out with a hammer.
Use a large hose clamp around the new one to compress it to get it started in the casting. The cover bolts will press it in the rest of the way.
Make note if there is a drain groove on the new bushing. It goes toward the bottom.

Good luck.