Grinding sound when going slow

[aerosly]

My '85 280SE has begun to make a grinding sound when I'm going really slow (up to 5 mph). It sounds like brakes would sound if the pad was completely gone and it was pure metal-on-metal... but it can't be the brakes because it happens whether I'm slowing down or speeding up.

Any ideas what could be causing this noise? Is it a wheel bearing or something?

[spanners]

Possibly a piece of debris that has got into one of the brake calipers.

Jack each wheel up one at a time and spind it by hand to identify which one.

Then remove the pads and clean the caliper out.