The need to replace a GMC oil pan is not typically because it has become worn out. This is a metal component that should last the life time of your GMC truck. The most common reason why this part would need to be replaced is when the driver of the truck runs over an obstacle in its pathway that pierces the oil pan causing it to no longer be able to contain oil or keep the road debris out. This is rare, but has occurred enough that the GMC engineers designed their engine and placement in the vehicle so the oil pan can be removed and replaced without the need for pulling the entire engine from the truck. Depending on the clearance of the truck, it might not even have to be lifted into the air for access to be granted the technician that will perform this task. Once the oil is removed the old GMC oil pan can be removed. With the underbelly of the engine exposed, all of the components should be inspected for damage. The most commonly damaged item in this section of the engine when the oil pan is pierced is the suction line for the oil pump. If this part is smashed or bent, it should be replaced so the flow of oil to the engine is not impaired once the repairs are completed. With the oil pan removed, and before the new one is put into place, all of the old gasket material must be removed so a good seal can be made. This has to not only include the paper or cork material but also the seals on the bearings at each end of the pan. Once in place the pan should be torqued down and then the GMC truck is ready to fill the need of the owner.