Things You'll Need
8-quart drain pan
Transmission-filter seal tool
Dexron III automatic transmission fluid
Changing the transmission filter on your 2002 Silverado is similar to changing the oil filter, in that you'll need to change the transmission fluid at the same time. The filter is mounted to the transmission with the pan covering it; draining the transmission fluid first makes this much easier. Note that this only applies to a truck with an automatic transmission, as a manual transmission does not use a fluid filter. On average, you need to replace the filter and fluid every 30,000 miles or 30 months for this model.
Raise the truck and support it on jack stands. Place your oil-drain pan under the transmission pan so it is directly underneath the drain plug.
Loosen and remove the drain plug with a flare-nut wrench and let the fluid drain into the pan. Install the plug back into the pan once most of the fluid has drained.
Unbolt and remove the heat shield on the transmission's right side using your wrench and then disconnect and unbolt the shift link cable from the left side.
Remove all of the transmission pan's bolts with the wench and then pry it off of the truck using a large flat screwdriver.
Pull down and pry the transmission filter off the transmission. Pry the seal out of its mounting hole in the transmission using a special removal tool.
Clean off the transmission's gasket surface using lacquer thinner or acetone.
Clean the inside of the transmission pan with a solvent. Dry off the pan with compressed air, as a towel can leave fibers that will contaminate the fluid.
Install the replacement transmission filter onto the transmission; make sure the new filter has a seal installed on it (most come with one pre-installed).
Connect the transmission pan to the truck with a new gasket placed on the inner flange. Tighten each of the bolts a little at a time with a torque wrench if possible until they are all at 97 inch-pounds.
Reinstall the shift-link cable and the heat shield.
Add four quarts of transmission fluid through the filler tube in the engine compartment with a funnel's aid.
Run the engine at fast idle with the truck in Park and the parking brake on. Shift into every gear and then back to Park. Let the truck idle a few minutes more and add extra fluid to the proper mark if needed.
Changing the fluid when it is warm from the engine will make it drain easier; however, you will risk getting burned from the fluid.