Occasional dry bearing noise

[tkd_M119]

92 W124 400e - 65K had 60K service done

I've been having what I can best descibe as a dry bearing noise that come through my steering column. It only lasts at most a couple of seconds and will happen only once or twice during a single drive. It seems to happen when the vehicle has been in operation for more than 1/2 hr. Most often happens when I've come off the freeway and am comming to a stop. But it occassionaly happens when lightly accelerating or even at 40MPH cruise. I can go for almost a week without hearing this noise. Then I'll hear it at least once a day for several days.

Any thoughts?