howling/whining towards the rear
 

My radio broke so my hearing of noises has become more sensitive. I have a faint howling/whining noise from the rear of the car between 40-50 MPH. Its seems to do it with or without load. For example, coasting downhill. I'm starting to think its related to right hand curves, but either uphill or downhill - i.e. slightly worse when cornerning, but not much.

Is this likely a tire, wheel bearing, or the differential?

The differential oil comes out very clean every 30Kmi & I've been using it for 78Kmi (currently has 258Kmi). Wheel carriers/bearings also have 258Kmi on them.

From what I've read, pinion bearings are usually the problem when load is applied, carrier bearings are not usually load related. I have one or two tires I can swap on the rear to check. If its the wheel bearing, would I be able to feel play? Or do I need to "drive it" on a lift and listen with a stesthoscope.

Thanks,

This is on my 1987 300D.

rear end noise
 

I just had to go thru the same diagnosis. Jack the car up and put it on 4 stands. run it in drive with the wheels spinning untill you get the noise. have someone hold this speed, or use a brick on the gas. go under the car with a stethescope, or long screwdriver to your ear. my noise was in the rear wheel bearing. it was quite obvious with the stethescope.