Check the cv joint boots for cracks, leaks, or dry-rotting. The outer boot is relatively easy to replace and is inexpensive. The one thing to be very careful of is to torque the axle nut to the specified value. GMs call for a lot, typically 180 to 240 foot pounds. Do not place the vehicle's weight on the wheel until that nut is torqued. It will be permanently damaged and become noisy if it is not held together by the cv joint and nut.