Crankshaft rear main seal replacement requires the removal of the transmission and flywheel, with caution advised to ensure that grooves and crankcase seams are filled with special Loctite® sealant to prevent oil leaks. Begin by removing the transmission, followed by the clutch pressure plate and disc for manual transmission vehicles, and then the flywheel. Drain the engine oil, and if necessary, scrape off the rubber coating to expose the six removal openings on the crankshaft rear main seal. Use the BMW special tool 11 9 200 to pull out the seal by inserting sheet metal screws into the removal openings and tightening them snugly. Slowly screw in the seal remover spindle to extract the seal. Before installing the new seal, clean the seal seating surface and thoroughly degrease the crankcase seams, applying a light coat of engine oil to the seal lip running surface on the crankshaft flange. Position the crankshaft seal and installation sleeve against the crankcase opening, taking care not to kink or damage the sealing lip, and ensuring the seal grooves center on the crankcase seams. Coat both grooves on the seal with Loctite® 171000 primer and allow it to dry for about one minute. Press the seal in as far as possible by hand, then remove the installation sleeve. Fit BMW special tools 11 9 182 and 11 9 184 to the crankshaft flange, place the spacer ring over the seal, and use BMW special tools 11 9 181 and 11 9 183 to press in the seal before removing the special tools and spacer ring.
