Q: How to replace the oil pan on 2003 GMC Savana 3500?
A: To remove the Oil Pan, if available all wnve drive (AWD) remove the inner axle housing nuts & washers from the bracket then support the front drive axle with an appropriate jack. Remove the differential carrier lower and upper mounting bolts and nuts if it has awd then lower the front drive axle. Lift the transmission cover bolt, bolts on crossbar, crossbar itself then the cover bolt and cover off. Drain engine oil and remove engine Oil Filter, install Drain Plug and Oil Filter again snug. For the automatic 4l60-e transmission, remove the transmission bolt and stud on the right and bottom, left bolt; the removal of the transmission converter cover bolts is required for the 4l80-e automatic transmission. Remove the oil level sensor electrical connector ( 6 ) , remove the battery cable channel bolt , slide the channel pin out of the Oil Pan tab and remove the positive battery cable clip bolt . Take out the Oil Pan bolts and Oil Pan so that no other dirt gets into the oil passage. Drill off the Oil Pan Gasket retaining rivets (2) if required, then remove and move the gasket and rivets. Service the engine Oil Pan by cleaning and including if needed. For installation, a 5mm (0.20 inch) bead of sealant gm p/n united states 12378190 or equivalent should be applied to the engine block on the tabs of the front rear cover gaskets which project into the Oil Pan surface. Pre-assemble the Oil Pan Gasket to the pan, gasket install pan, gasket and bolts install to engine block tighten Oil Pan bolts until snug with out over tighten. When installing the transmission converter cover bolts up snug on the 4l80-e automatic transmission, if possible. For the 4l60-e automatic transmission with transmission bolt and stud tighten to the right side, until snug, followed by the bottom bolt to left side. Oil Pan-to-front cover bolts - 25 nm (18 ft. Lbs.), Oil Pan-to-rear cover bolts - 12 nm (106 inch lbs.), converter cover and transmission bolts/stud - 50 nm (37 ft. Lbs). Install the positive battery cable clip bolt (9 Nm (80 inch lbs.)) and slide the channel pin into the Oil Pan tab, install the battery cable channel bolt (12 Nm (106 inch lbs.)) and connect the oil level sensor electrical connector (6), install the transmission cover and bolt (tighten the bolt to 12 Nm (106 inch lbs.)). Mount the crossbar and the crossbar bolts, torqued to 100 nm (74 ft. Lbs.), next mount the transmission cover bolt and tighten to 12 nm (106 inch lbs). Raise front drive axel to position, install differential carrier upper mount bolt and nut until snug without tightening if awd and then install differential carrier lower mount bolt and nut, tighten to 100 nm (75 ft. Lbs). Finally, to the bracket, mount the inner axle housing washers and nuts, tightening to 100 nm (75 ft. Lbs.), remove the jack from the front drive axle, and put new engine oil and a new Oil Filter.