Sounds like ball joints to me. They carry the weight of the front end of the car, so not much clearance has to occur for them to make a lot of noise. Once you hear noise coming from them, they're done. They'll just get worse and worse as time goes on. Depending on how wet your climate is, their degradation can be fast or slow.

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Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]