We have 95 ES300. Getting a grinding noise and vibration in seat (not stearing wheel) above 30 mph. Doesn't seem better or worse on turns. Sounds like a gear grinding. Car has 200k miles. Could this be CV joint, or other axil problems? Any help appreciateed.

 

A bad cv joint will grind more when you turn the wheel, try turning the wheel to both stops while slowly driving. Also look underneath the car, are the cv boots in good shape? Or are they torn up and slinging grease everywhere. If it is grinding at 30, you could downshift into first, and see what speed you hear the noise, and then upshift to 2nd. Is the noise at the same speed. If so, that would indicate wheel bearings or cv's.
Next get a GOOD set of jackstands, lift the front of the car, With the e brake on and the engine off. Put the tranny in neutral and spin the wheels by hand. Place your hands at 3 and 9 o'clock position. Then at 12 and 6, rock the wheel back and forth. There should be almost no discernible movement. Many times if a wheel bearing is going out, this last test will prove it beyond any doubt. If the wheel rocks, the bearing is bad.

 

Thanks for reply George. It turned out to me something simple. The rear tires were delaminating. don't know how this happened.