I have a 2006 RL AWD with 147000 miles, and recently the car has started making a very loud grinding noise from the front end around the AWD portion of the transmission only while making either a left or right turn under acceleration. While driving forward under acceleration the noise is gone. I put the car on jack stands off the ground to listen for the noise but it's quiet with no noise while off the ground.Any ideas?

 

Did you check the suspension and steering components while you were under there?

 

Was this in the snow? Were any of the wheels slipping?

 

Cv joints?

 

Check the half shaft bearing and the hub bearings.
The hub bearing is what the wheel rotates on that is attached to the knuckle upright. The bearings could be gone. Also while your under there, check that the drive axles have no back and forth play in them. They should be tight if you push and pull from inside to outside.

 

The problem turned out to be a bad engine mount on the passenger side of the engine.