I have a noise in the front end on my 4x4. Back the truck up and start to turn either way a popping noise comes up. It won't do it again until you back up again and go forward. Had the front lifted to level with rear and checked all the susp. and brakes on this. Even loosened and retightened everything. Dealer said they can't hear it, but my alignment guys can. Could it be the brake calipers or mounts? Alignment checked again and the lift was retightend again but still no cure. Help.