Replacing timing belt

a 2003 chevy silverado has a timing chain. In order to change this, you will have to remove the fan and clutch, the water pump, both serpentine belts, and the crankshaft pulley. You cannot reuse the bolt for the crank pulley, so you will have to buy a new one. You will also have to replace the gaskts for the timing chain. Anyways, once those are off, you remove the cover for the timing chain, and you will be able to unbolt and remove the timing chain and sprockets. Note where everything is, so you can return it to the exact same place. Once that is done, put everything back like you saw it when you took it apart, and you should be good to go. Remember to get new gaskets for the water pump, (you should replace the thermostat while you're in there as well) and make sure your belts are in good shape. Also check your idler pulleys and tensioners to make sure they're not worn out. Good luck, and enjoy your time under the hood.