I have a 2005 nissan xterra 4-wheel drive. while driving it in snow, ice, wet roads or simply stopping quickly, i hear a horrible grinding noise from the front end. it happens when i apply the brakes coming to a stop. it has to be a condition where the wheels may lock up. also, the brakes let the vehicle "loose" for several feet and/or seconds before the grinding begins. i am used to the fluctuation of the brake pedal with an abs system. however, i had never heard a sound that reminded me of grinding aluminum cans in a coffee mill. i took it to the service dept when this first happened (december 2005; last incident, april 2010) and they have assured me that this is how the abs is supposed to sound, feel and work. my husband noticed the same feeling/sensation and asked what was wrong with the brakes. i told him nissan says that is how they're supposed to work. it doesn't sound acceptable that an automobile company would produce a safety system that sounds/feels like your differential is being ground into little metal pieces. *tr