The steering shaft on a Chevrolet Silverado connects the steering column to the steering box. On some models of the 2004 and newer Silverados, the steering shaft has a known problem in that it can make a clunking sound when making a turn. The fix is to replace the steering shaft with a new, upgraded model from the dealership. This can be done in about 30 minutes with the proper tools.
Open the driver's door. Turn the steering wheel from side to side until it locks in place.
Pop the hood. Locate the steering shaft, which is on the driver's side of the firewall, and has an accordion boot around it. Unbolt the top bolt on the shaft using an open-end wrench and the 3/8-inch ratchet and socket.
Push down the top of the steering shaft down towards the steering box using your hands. Then pull the steering shaft off of the steering box with your hands.
Push the replacement steering shaft onto the steering box. Compress the shaft and then pull it back to bring it to the steering column connection. Bolt it in place using an open-end wrench and the ratchet.
