[BenTwombly]

I hear a slow, low groan, a low pitch vibration, from the rear when traveling at very-very slow speeds, typically in crawling traffic (I live in metro New York City). It seems to cycle with wheel speed. It goes away when speeds reach a few miles per hour. I experienced the same groan on the 1985 500SEL, and 1986 560SEL. Searching for "groan" threads refer to wheel bearing failure. In previous cars I have had wheel bearing failure and it sounded very different, and was typically at high speeds. I am no expert but it sounds to me like drum brake dragging? Is the emergency brake a separate system? Is it a drum system? Resetting and re-releasing the emergency brake had no apparent effect.

Any ideas?

 

[MBL87560SEC]

Hi Ben,

Yes, the E/brake is a drum system. The drums are part of the rear discs L&R.

Sounds to me as though something is dragging.

Does the sound go away if you touch the brakes while maintaining the low speed with your other foot?

Does one wheel feel hotter than the other?

Ideas to ponder... MBL

 

[BenTwombly]

MBL: Great suggestions. I'll check the next time I take it out and write back. Thanks. --Ben

 

[dtkw]

My car now make a soft humming noise at around 40mph, and only at that speed. Any idea?