To change the Oil Pan on a 4 wheel drive, one should first disconnect the negative cable from the battery, take the oil level indicator, the front Differential assembly, the
Starter, and the transmission cover. Drip pan drain the engine oil and take it into a proper container by unbolt the Oil Pan
Drain Plug. Next remove the remote oil filter pipe adapter, the bolt holding together the remote oil filter inlet and outlet hose clip to the Oil Pan, and the stud for the Starter wire harness bracket and transmission oil cooler pipes if equipped. Take off the Oil Pan rear nuts access plugs, transmission Oil Pan bolts and dispose of engine oil level sensor, as they cannot be reused. Take off the Oil Pan and gasket, clean all sealing surfaces, apply on the junction of the engine front cover and crankshaft rear oil seal housing a 5 mm (0.197 inch) wide and 25 mm (1.0 inch) long bead of adhesive gm p/n 12346141 or equivalent. Replace the new Oil Pan Gasket into the Oil Pan groove; the Oil Pan should align flush or front no more than 0.3mm (0.011 inch) behind the face of the engine block. Slide the Oil Pan back against an appropriate straight edge, bolt and nut the Oil Pan without tightening, measure pan to the transmission house clear gauge by using a feeler gauge. In the case where the clearance shows more than 0.3mm (0.011 inch) at any of the measurement points, then the process is repeated for alignment. Tighten the Oil Pan bolts to 25 nm (18 ft. Lbs.) in sequence, check the clearance again, and install a new Oil Pan Drain Plug seal onto the Oil Pan Drain Plug with a tightening to 25 nm (18 ft. Lbs.). Replace the new engine oil level sensor if it is available (torque to 13 Nm 115 inch lbs.), and then install transmission to Oil Pan bolts, tighten them to 47 nm (35 ft. Lbs.). Reinstallation of the access plugs for the Oil Pan rear nuts, the stud for the Starter wire harness bracket and the remote oil filter pipe adapter. Secure the oil filter inlet and outlet hose clip bolt to a 10nm (88 inch lbs.), also the transmission cover bolts to 12nm (106 inch lbs.). Finally, replace the Starter motor, front Differential assembly, and oil level indicator, and oil the engine plus reconnect the negative cable of the battery.