GM 12554314
Rear Main Seal

The crankshaft rear oil seal replacement process requires removing both the Transmission Assembly and engine Flywheel before installation. A suitable tool must be inserted into the access notches to extract the crankshaft rear oil seal before careful prying of the seal out of its housing. Remove the damaged seal then wipe away all rust and dirt from the targeted area. Apply two to three drops of clean engine oil to four surfaces: the bore of the crankshaft rear oil seal housing, the outside diameter of the engine Flywheel pilot flange, the outside diameter of the Flywheel locator pin, and the Crankshaft Seal surface. Look for imperfections on the j 35621-b rear main seal installer (J 35621-B) flange surface before you fix minor damages with fine grade emery cloth while also keeping the seal lip free from contaminants. Place a small droplet (2 to 3 drops) of fresh engine oil onto the outside surface of the sleeve that holds the crankshaft rear oil seal. Spot the crankshaft rear oil seal onto the j 35621-b before placing it on the rear crankshaft part. Use hand pressure to tighten down the tool bolts when they reach a comfortable tightness. Proper alignment is critical; maintenance success relies on achieving tight installation of the seal which should be oriented directly to the housing bore for high quality performance. Screw the j 35621-b wing nut into the housing bore until the tool meets maximum resistance at the bottom and seals become completely flush with the housing bore. First use a clean rag to wipe away engine oil from the crankshaft surface then extract the tool and remove it from the crankshaft operation. Reinstall both the Transmission Assembly and the engine Flywheel as the last step.

Finally, reinstall the engine flywheel, transmission assembly, and oil pan.

The tools required include the J 35468 (J 35468) Cover Aligner Seal Installer.

Release the tool by turning the wing nut counterclockwise and remove the J 35621-B from the crankshaft, wiping off any excess engine oil with a clean rag, and finally reinstall the engine flywheel and the transmission assembly.

Disconnect the battery negative cable from the battery.

Remove the transmission assembly.

Raise the vehicle and remove the drive belt from the vehicle's drive pulleys.

Reinstall the crankshaft balancer.

Remove the flywheel using the Engine Flywheel Replacement procedure.

Remove the crankshaft rear oil seal from the crankshaft rear oil seal housing.

Remove the transmission assembly.

Remove the crankshaft balancer.

Inspect the engine front cover seal bore and the crankshaft balancer sealing surface for any damage.

Tighten the oil pan, reinstall the flywheel, and finally, install the transmission assembly.