GM 12609074
Oil Pan

The replacement of oil pans in 4wd vehicles commences by raising and supporting the vehicle. The first step involves removing skid plate bolts and skid plate on 1500 series vehicles if they are equipped. The 2 rear skid plate bolts need to be loosened on 2500 series vehicles before removing the 2 front bolts and skid plate when present. Put a suitable drain pan under the Oil Pan Drain Plug then carefully unscrew this plug to let all oil flow out completely before redoing the plug tightly. When draining oil from the filter direct it to the drain pan. Remove the Oil Filter (437), let it drain fully before reinstalling it until it becomes hand tight. Both series transmission crossbars need crossbar bolts/nuts removal before taking out the right and left side transmission cover bolts and covers. A transmission with 4l60-e/4l70-e or 4l80-e requires the removal of two lower bolts. If equipped with the 6l80-e automatic transmission you need to remove both the lower left bolt and lower right stud. Disconnect the engine harness electrical connector from the oil level sensor along with removing the engine harness clip from the transmission oil cooler line bracket along with the battery cable channel bolt. You should slide the channel pin from the Oil Pan tab then detach the oil cooler lines from the clip (unless your vehicle has this equipment). First a mechanic must remove the Oil Pan transmission cooler line clip bolt alongside its clip from the Oil Pan before moving onto the next step of unbolting the Oil Pan and finally removing the pan itself. Drill out Oil Pan Gasket rivets before you discard the gasket and rivets when retaining the Oil Pan for reuse. The installation starts by setting a new Oil Pan Gasket onto the Oil Pan followed by applying a 5 millimeter (0.20 inch) bead of sealant onto the engine block tabs of the front and rear cover gaskets. Install one Oil Pan bolt through the gasket and position and install the Oil Pan while tightening the remaining bolts until they become snug. Install the lower right transmission stud first followed by the lower left bolt to achieve initial torque for vehicles using the 6l80-e automatic transmission. You should first tighten the 2 lower transmission bolts to a snug fit for 4l80-e and 4l60-e/4l70-e automatic transmissions. Tighten the Oil Pan bolts and Oil Pan-to-Oil Pan front cover bolts to 25 n.m while the Oil Pan-to-rear cover bolts require a torque value of 12 n.m and the transmission bolts/stud need a torque of 50 n.m. Put the transmission oil cooler line clip into place before installing its bolt to the Oil Pan and tightening it to 9 n.m (80 lb in). Fasten the transmission oil cooler lines to the clip and slide the channel pin through the Oil Pan tab while aligning the channel. Then install the battery cable channel bolt with a torque setting of 12 n.m (106 lb in). Use engine harness clip and hook up the electrical connector to the transmission oil level sensor before fastening the bracket to the transmission oil cooler line. Technical experts should strip both series of their original adhesive residue along with cleaning bolt threads using denatured alcohol before applying threadlock gm p/n 12345493 (Canadian P/N 10953488) to the bolt threads. The 2500 series crossbar requires its nuts tightened to 120 n.m (89 lb ft) and 1500 series requires bolts tightened to 100 n.m (74 lb ft). First position the left side transmission cover before installing the cover bolt to achieve 12 n.m (106 lb in) torque. The right side cover bolt should then be installed next. Reusing the old Oil Pan requires you to replace the Oil Filter with a new unit and apply engine oil to the seal. Tighten the filter to a torque specification of 30 n.m (22 lb ft). Reinstall the front differential carrier then position the Oil Pan skid plate for 2500 series vehicles and secure the 2 rear bolts and 2 front bolts with 28 n.m (21 lb ft) torque if equipped or secure the 1500 series skid plate and its bolts to 28 n.m (21 lb ft). Fill the engine with fresh engine oil and begin the engine to check for any fluid leakage. Then lower the vehicle down.

Vehicle service begins by raising the vehicle then supporting it to perform the Oil Pan replacement on 2wd vehicles. Owners of 1500 models should disconnect skid plate bolts before removing the skid base plate except in cases where no skid plate exists. Owners of 2500 models need to disarm rear Oil Pan skid plate bolts before taking out front bolts and skid plate if skid plate exists. Begin by hanging the steering rack downwards after unbolted. Place a proper drain pan under the Oil Pan Drain Plug to drain all oil which you must tighten properly later. The drain pan needs installation beneath the Oil Filter before removing it (437) until all fluid drains before reinstalling it securely. First remove the bolts on both transmission covers before breaking away the left and right side transmission cover pieces and then remove all crossbar nuts and bar elements from both series types. 2 lower transmission bolts need removal for vehicles equipped with either a 4l60-e/4l70-e or 4l80-e automatic transmission. During 6l80-e automatic transmission service remove both the lower left transmission bolt and the lower right transmission stud. Start by removing the transmission oil level sensor engine harness electrical connector then detach the engine harness clip from the transmission oil cooler line bracket before removing the battery cable channel bolt to slide the channel pin out of the Oil Pan tab. Cars with transmission cooler lines will need those lines removed from the clip before continuing to remove the transmission oil cooler line clip bolt and clip from the Oil Pan along with the Oil Pan bolts and Oil Pan itself. Before reusing the Oil Pan users should drill out any necessary Oil Pan Gasket rivets before removing and discarding both gasket and rivets. The critical step for structural Oil Pan alignment requires new Oil Pan Gasket installation and prohibits gasket reuse. Position the new Oil Pan Gasket onto the Oil Pan before applying a 5 mm (0.20 in) bead of sealant that spans 20 mm (0.80 in) on both engine block tabs of the front and rear cover gaskets. After this, fit one Oil Pan bolt through a hole and into the gasket. Position the Oil Pan while securing all remaining Oil Pan bolts until they achieve a secure fit. Before moving to the next step you should install both the lower right transmission stud and lower left transmission bolt to a secure position on vehicles with 6l80-e automatic transmission components. The installation of 2 lower transmission bolts reaches their necessary snugness on both 4l80-e and 4l60-e/4l70-e automatic transmissions. Install the Oil Pan completing tightness at 25 n.m (18 lb ft) and Oil Pan-to-Oil Pan front cover bolts at 25 n.m (18 lb ft), Oil Pan-to-rear cover bolts at 12 n.m (106 lb in), and transmission bolts/stud at 50 n.m (37 lb ft). The transmission oil cooler line needs its clip installed on top of the Oil Pan and the bolt tightened to 9 n.m force (80 lb in metric). Position the channel onto the Oil Pan tab before sliding the channel pin through the tab. Then bolt and tighten the battery cable channel to 12 n.m (106 lb in). Finally if your vehicle has cooler lines install them to the clip. Connect the oil level sensor electrical wires through the engine harness connector then bolt the engine harness clip onto the transmission oil cooler line bracket. Both vehicle series require the original adhesive patch removal, denatured alcohol cleaning of bolts followed by gm p/n 12345493 threadlocking (Canadian P/N 10953488) application before crossbar installation. Install the crossbar and crossbar bolts and nuts according to these torque specifications: 120 n.m (89 lb ft) for 2500 series and 100 n.m (74 lb ft) for 1500 series. Start by fitting the left side transmission cover before installing and torquing its cover bolt to 12 n.m (106 lb in) and following with right side transmission cover bolt installation. When using an existing Oil Pan install a new Oil Filter (437), apply clean engine oil to the seal before tightening the filter to specification at 30 n.m (22 lb ft). Screw the Oil Pan Drain Plug (430) at 25 n.m (18 lb ft) tightness. Then lift the steering rack into position for bolt installation before securing the left bolts to 200 n.m (148 lb ft) and right bolts to 100 n.m (74 lb ft). Users should install the Oil Pan skid plate by tightening the rear bolts on 2500 series vehicles before putting on front bolts (if equipped) and securing them to 28 n.m (21 lb ft). The 1500 series requires installation and bolt tightening of the skid plate to match the specified values. Lower the vehicle before filling the engine with new engine oil and begin engine operation for leak checks.

To replace the Oil Pan, raise and support the vehicle first. If fitted, unbolt and remove the Oil Pan skid plate and bolts, then drain the oil by removing the Drain Plug and Oil Filter. For removal of 2-wheel drive, crossmember bolts and bar. For 4 wheel drive do the same and also remove the front differeential carrier. Next, released the engine harness bracket bolts, starter and transmission cover, engine harness and transmission tube bracket are followed by two engine wire harness bracket bolts. In case of a transmission, first you need to remove the manual and automatic transmission bolts, then take out the Oil Pan bolts and nuts for removing the Oil Pan itself, and discard the old gasket. Clean and inspect the Oil Pan as required. While fitting, use a 5mm (0.197 in) wide, 25mm (1.0 in) long, bead of adhesive on the front cover to engine block junction and rear oil seal housings to engine block junction, ensuring a new Oil Pan Gasket is fitted in Oil Pan groove. The Oil Pan should be placed flush or forwards up to a distance of 0.3mm (0.011in) from the rear face of the engine block. Mount the Oil Pan, position the gasket into the grooves, and slide it back to a straight edge with pressure. End of block bolts and nuts to the fuel filter housing by hand while wearing gloves until tight a feeler gauge for measuring the Oil Pan to transmission housing clearance. If it surpasses 0.3 mm (0.011 in), start aligning it again. Loosen all the Oil Pan bolts and nuts, retighten them to 25 n.m (18 lb ft), then check the clearance once more after tightening them in the specified sequence. Mount a new Drain Plug o-ring seal on the Drain Plug and tighten it 25 n.m (18 lb ft). The filter can be installed by tightening the, resinstall the, transmission cover and tighten the bolts to 12 n.m (106 lb in ), and the manual and automatic transmission bolts to 50 n.m (37 lb ft). Replace the engine wire harness bracket bolts, engine harness and transmission tube bracket bolt with a new one and tighten it to 9 n.m (80 lb in). Connect the Starter, as well as the oil level sensor electric connector, and tighten the engine harness bracket bolts to 12 n.m (106 lb in). For 2wd, perform the reverse installation of crossmember and bolts, tighten it to 100 n.m (74 lb ft) for 4wd, re-assemble the front differential carrier and cross member, also to 100 n.m (74 lb ft). If necessary place back oem Oil Pan skid plate and bolts, tighten to 20 n.m (15 lb ft). Apply clean engine oil to lubricate the Oil Filter gasket, fitting the Oil Filter and tightening the latter to 30 n.m (22 lb ft). Lastly, lower the vehicle and pour the required amount and right grade of engine oil into the engine.

If you need to change the Oil Pan of the 4wd vehicles, first lift the 4wd up and support it. 1500 series; remove the Oil Pan skid plate bolts and skid plate if so equipped; for 2500 series, remove 2 rear Oil Pan skid plate bolts, and 2 front bolts and skid plate if equipped. Looseenting. Remove the front differential carrier, unbolt the steering rack and let the latter hang downward, thereafter, position an appropriate drain pan beneath the Oil Pan Drain Plug (430) and unscrew the Oil Pan Drain Plug and allow the oil to pour off and afterwards, reinstall the Oil Pan Drain Plug securely. Set the drain pan under the Oil Filter, remove Oil Filter (437) and wait for the oil to drain out before reinstalling the Oil Filter securely. Tap off the right and left side transmission cover bolts and cover, followed by the crossbar on both the 1500 and 2500 series vehicles. For the vehicle equipped with a 4l60-e/4l70-e automatic transmission, remove the 2 lower transmission bolts; for 4l80-e, remove the 2 lower transmission bolts; for 4l80-e, come off 2 lower together bolts; for 6l80-e, have to come off lower left together bolt and lower right together stud. Unplug the engine harness electrical connector from oil level sensor, remove the engine harness clip from transmission oil cooler line bracket, and remove the battery channel bolt. Slide the channel pin out from the Oil Pan tab, and with the oil cooler lines pulled from the clip for the subjected automatic transmissions. First remove the transmission oil cooler line clip bolt &clip from the Oil Pan, then the Oil Pan bolts, then the Oil Pan. Drill out any Oil Pan Gasket rivets if needed, remove and discard the Oil Pan Gasket and rivets. When installing, new Oil Pan Gasket apply a 5mm (0.20 in) bead of sealant 20mm (0.80 in) on the tabs of the front and rear cover gaskets on engine block and then install the Oil Pan and the remaining Oil Pan bolts and until fastened. For 6l80-e automatic transmission vehicles, install the oil cooler bracket and tighten the lower right transmission stud and lower left transmission bolt until tight; for 4l80-e and 4l60-e/4l70-e, install their respective lower transmission bolts until tight. Upgrade the peculiarity of the Oil Pan and Oil Pan-to-Oil Pan front cover bolts to 25 n.m (18 lb ft),peculiarity peculiarity of Oil Pan-to-rear cover bolts to 12 n.m (106 lb in),peculiarity peculiarity of transmission bolts/stud to 50 n.m (37 lb ft). Install and tighten the transmission oil cooler line clip with the bolt by measuring 9 n.m (80 lb in) on the Oil Pan. The oil cooler lines inspection on clip for the respective automatic transmissions, at the channel position, slide the channel pin into the Oil Pan tab, and on battery cable channel bolt tightening to 12 n.m (106 lb in). Fasten the engine harness electrical connector to oil level sensor and reinstall the engine harness clip to the transmission oil cooler line bracket. For both series, strip away any indication of the adhesive patch to start with, clean the bolt threads with denatured alcohol and apply threadlock gm p/n 12345493 (Canadian P/N 10953488) or equivalent to the threads of the bolts. Install crossbar and bolts/nuts for 2500 series by using nuts tightening torque at 120 n.m (89 lb ft) while for 1500 series use the nuts tightening torque of 100 n.m (74 lb ft). Install the left side transmission cover and the cover bolt with 12 n.m (106 lb in) followed by the right side cover bolt. If the old Oil Pan is to be reused, remove and extract an old Oil Filter and install a new Oil Filter (437), lubricating the seal with clean engine oil and tightening to 30 n.m (22 lb ft). Make sure the Oil Pan Drain Plug (430) settled at 25 n.m (18 lb ft), reinstalled the front differential carrier, lifted the steering rack and install the steering rack bolts, tightening the left side bolts to 200 n.m ( 148 lb ft) and the right side bolts to 100 n.m (74 lb ft). To 2500 series vehicles: install the Oil Pan skid plate and tighten the 2 rear Oil Pan skid plate bolts and install the 2 front Oil Pan skid plate bolts, if equipped, to 28 n.m (21 lb ft). For 1500 series vehicles, position the Oil Pan skid plate and install the bolts if equipped and tighten them to 28 n.m (21 lb ft). Finally, lower the car, and fill the engine with new engine oil, and switch on the engine to check for leaks.

Clean and inspect the engine oil pan as needed.

Remove the transmission cover bolt and cover, drain the engine oil, and remove the engine oil filter, then re-install the drain plug and oil filter until snug.

Tighten to 30 N.m (22 lb ft).