Mechanic states loud noise may be differential B?How much will this be to fix?

Thanks for replying! When driving over 20mph and taking left turns. It makes a grinding sounds (not too loud). So exactly what you've stated above.... So no part needs to be replaced just fluids? Is it ok to drive?

I do believe it is safe , yes no parts , only synthetic gear oil and I also finally remembered .... the additive is called a 'friction modifier' and , again , if memory serves me , it takes two bottles(they are small). Probably best bet is to verify with a dealers parts department , they know their product best (one can only hope!).