Thread: Do i need to remove crankshaft to replace rear main seal

Tools Required
•J 33196 Rear Crankshaft Seal Installer

Removal Procedure

1.Remove the engine flywheel.
Important: Make sure not to damage the crankshaft outside diameter surface or chamfer with any tool.
2.Remove the crankshaft rear oil seal. Insert a flat-bladed tool through the dust lip at an angle. Pry out the crankshaft rear oil seal by moving the handle of the tool towards the end of the crankshaft. Repeat as necessary around the crankshaft rear oil seal.
3.Inspect the inside diameter of the bore. Correct or replace the crankshaft rear oil seal housing as required.
4.Inspect the crankshaft for nicks or burrs on the surface that contacts the crankshaft rear oil seal.
5.Repair or replace the crankshaft as required.

Installation Procedure

1.Apply engine oil to the inside and the outside diameter of the new crankshaft rear oil seal. Slide the new crankshaft rear oil seal over the mandrel until the back of the crankshaft rear oil seal bottoms squarely against the collar of the J 38196.
2.Install the crankshaft rear oil seal using the following steps:
Notice: Refer to Fastener Notice in Service Precautions
2.1. Attach the J 38196 to the crankshaft by hand, or tighten the attaching screws.
•Tighten the screws to 5 Nm (54 in. lbs.) .
2.2. Turn the T-handle of the J 38196 so that the collar pushes the seal into the bore. Turn the handle until the collar is tight against the case. This will ensure that the crankshaft rear oil seal is seated properly between the crankshaft and the crankshaft rear oil seal housing.
2.3. Loosen the T-handle of J 38196 until the handle comes to a stop. This will make sure that the collar will be in the proper position for installing another new crankshaft rear oil seal.
2.4. Remove the attaching screws.
3.Install the engine flywheel.
4.Check and fill the crankcase as necessary.
5.Inspect for leaks.

I remove the rear engine cover to do this job. Reason being is the rear engine cover gasket is usually seeping or the bolts are not torqued to spec as they have no loctite on them and a low torque spec. I pull it, do the seal (without the proper tool, you can do it...just takes a little ingenuitiy), redo the rear cover gasket with rtv at the bottom inch and some loctite and to torque spec on the bolts.

never had one leak from the seal, its usually leaking from the pan or in one case it was leaking oil from the rear cover gasket (and coolant)

replace the rear cover gasket, those paper gaskets get brittle over time and corrosion causes it to split and push out

im at the point i always do the rear cover since almost 75% of the ones i pull of were seeping coolant/split gaskets.

the 06+ aluminum rar cover gasket doesnt fare any better as 2 of the 3 ive done were looking like 120k LIM gaskets...and that 3rd one only had 25k

pull off the flexplate and see if its actually the seal but yeah...never replaced one

Like James (SBC) mentioned, I often find people misdiagnosing an oil pan gasket when the rear cover gasket is seeping. I've also never had a rear main seal show signs of leakage either.

Originally Posted by BillBoost37

I remove the rear engine cover to do this job. Reason being is the rear engine cover gasket is usually seeping or the bolts are not torqued to spec as they have no loctite on them and a low torque spec. I pull it, do the seal (without the proper tool, you can do it...just takes a little ingenuitiy), redo the rear cover gasket with rtv at the bottom inch and some loctite and to torque spec on the bolts.

I agree with this. I didn't use loctite however and hope I'm not going to develop a leak over time... I don't think you can do this on most motor stand however. I installed the rear cover just about last on my build while the motor was hanging on the hoist before dropping it back in.