Check ur fluid levels.. I doubt its the diff. Its prob ur axle shafts taking the heat of the new coil overs.. They could have been worn already and now that there is more stress on them cause of the stiffer suspension you are hearing that. But thats just my guess. Maybe the guys who put them on didnt tighten something down all the way. Its possible ur axle nuts may be alil loose too. That happened to me awhile ago when i accidentally clipped a curb in my old 2.5i sedan and i would get something similar to the noise you have when cornering. Thats all i got though man. Lemme know what happens. Sorry to everyone else for the thread jack... Jus trying to help