droning from wheels or bearings or ???

[steelynorm]

1989 coupe manual.
so I have started to notice that the droning in my car has been getting louder.
It is not related to the engine or exhaust, because when I coast at speed the droning is still there.
noise increases as speed goes.

It sounds like I am driving on Mud tires.

I thought it was coming from rear, so I jacked my car up and checked for excessive play of rear bearings.. did not notice anything.
I swapped rear tires left and right, drove car and the noise is still there.

I am not ruling out front bearings either... I have had other cars that needed front bearings, and usually you can tell if you have a bad front bearing when you are taking corners and the noise becomes more noticieable.
That is not occurring at this time.

Any other ideas?

[roguetoaster]

If a bearing, it could be the driveshaft, and axle or, more likely, the differential as those all run at road speed all of the time.

Also remember, that bearings may not show wear with a visual inspection until loaded in some axis, so give everything a good shake when on the ground. You can also put the car up on jack stands in the rear and run it in gear if you believe you can do so safely. Do remember that axles will look wonky when at full droop and running, also simply minimize operational time in gear in that state.

For questionable bearings I suggest getting yourself an IR temperature reader and check for differences in temperature of components after a drive. If you do so, try and minimize brake usage before stopping, so use engine braking until almost stopped if practical for you.

[jbontke]

Sounds like wheel bearing if it increases noise with speed of travel. I have had bad wheel bearings that had no play in them and didn't change pitch when loaded/unloaded. I had to "feel" it move to identify the bad bearing.

[AndrewBird]

If the wheel bearings have never been replaced, they need to be. I'd replace them just to rule them out.

Tire wear could be the cause as well. Many tires get louder as they wear down.

[Das Delfin]

if the noise goes away or gets louder when you drive on a long sweeping curve, you know for sure it's your wheel bearing. You're best off replacing both. It's not that bad - buy the harbor freight "front wheel drive wheel bearing kit," a new axle nut retaining bracket (the one you hammer in after tightening the rear axle nut), and some large size sockets like 27mm, 30mm, 32mm, and 36mm, and you'll be able to do both your front and rear