One of my ball joints on my 88 190e, was making noise so I just changed out both of them! Do both, chances are if one is worn the other is worn or soon to be bad. At the same time, I took advantage of having the Control Arm bushings changed. Furthermore, had all tie rods and so forth checked while the mecanic was there. Also, while you are there, check the sway bar bushings (I had mine changed about a month ago).
The cost was very reasonable and the results were exceptional. The car handles, or at least feels, a lot more stable!
Insanity: doing the same thing over and over again and expecting different results.
2006 - Suzuki Gran Vitara (2.0 L fully equipped) Like this car so far except for trying to put on the seatbelt.
1988 - 190e - 2.3L - 172K miles (It now belongs to the exwife)
1999 - Chevy Blazer LS Fully Equiped - killed it June 2006
2001 - Honda Civic EX - 68K miles (sold June 2004)
1963 - 220S - Dual Carb 6 cyl. (sold)
1994 - Yamaha WaveRaider (fun to ride)