rear end? noise from my 300sd
 

Hello all. On my 85 300sd with 262k. When turning left, I hear speed dependant (speeds up or slows down on road speed). squeal, like brakes rubbing. I drive along a left turn bridge, hear the sound realwell as it bounces off the bridge barricades. I hit the brakes the sound continues, I apply the parking brake and the noise is still there. Drive straight,or a right turn, no noise. I am figuring that it is the differential as it would work on a turn, and something is bad. I thought it might be the axle drive shafts, but they are tight on both sides with good rubber boots. No leaks, no shiny spots where a tire might rub. So I am just about positive its the pumpkin ball. Any thoughts??

Is there/has there been any signs of abnormal tire wear?

Wheel bearings.

I second a wheel bearing...
 

It'll get so loud you'll swear a plane was landing nearby.

I had an '81 Subaru 4WD wagon with bad rear wheel bearings. It would go down the road straight with no noise. Any time you made a corner and the weight would transfer it would sound like somone was under the car with an angle grinder.