Steve, thanks for the thorough reply. Yes, you understood me correctly.
Your explanation has informed me how to proceed. When working on this item, I saw that the bolt holes on both ends of the lower control arm have been widened. When I put the jack under the spring, I observe that the whole bolt apparatus move up a bit. I can even see part of the hole in the control arm behind the head of the bolt. The control arm holes seem to have been reamed wider than appropriate by the flexing that no longer occurs with the bolt. Therefore, from what you point out, I conclude that I need to replace the lower control arm as well as at least no. 142 in your diagram but, more likely, all of no. 158.
The kingpin itself is well greased via the middle nipple and showns no sign of wear or wobble.
Should I anticipate that when doing this job, the unnumbered carrier in no. 158, which is where the bolt is frozen, will slide down off the kingpin easily? Or will I inevitably damage the kingpin in the process of dissassembling the lower bolt apparatus?
Have you any information as to the tightening torque for the castle nut on the lower control arm bolt?
Finally, I cannot get the top kingpin nipple to accept much grease either. This serves the eccentric bolt for wheel alignent. I do not detect any widening of the control arm hole, though. I may have forced a small amount of grease into it with a hand grease gun because I got loud squeaking to stop. Perhaps I shall try an air-powered grease gun at a shop.
Thanks for your kind help.
1959 M-B 220S cabriolet