Drain the cooling system and engine oil, and remove the oil filter. If working on a 3.5L engine, remove the intake manifold. Remove the valve covers and the crankshaft pulley. Take off the drivebelt tensioner and all accessory brackets attached to the timing cover, including the drivebelt, idler pulley, alternator, and crankshaft pulley. Remove the alternator bolt and swing the alternator out of the way. Remove the water pump, then take out the timing cover bolts and separate the cover from the engine block, gently prying at the seven spots around the timing cover until it comes off. Clean the gasket mating surfaces with brake system cleaner. While the cover is off, install a new crankshaft front seal and a new radial seal in the center of the timing cover before mounting it. Apply a 1/8-inch bead of RTV sealant to the mating surface of the cover and a 3/16-inch bead to the areas where the oil pan and cylinder heads meet the engine block. Slide the timing cover onto the engine, ensuring the dowel pins position it correctly, and install the bolts finger tight, starting with bolts 1, 2, 7, 8, 15, 17, 18, 19, 20, and 21, then tighten them to the specified torque within 35 minutes. Install the remaining parts in the reverse order of removal, then install a new oil filter and add engine oil and coolant. Finally, run the engine and check for leaks.