How to Replace an Engine’s Rear Main Seal

by Joe on October 10, 2011

After seeing the puddles and checking the other possibilities, you determine you’ve got a leaky rear main seal on your car; sorry.

This has the reputation for being a really difficult job, but with the right tools, attitude, and instructions, I think you’ll find it’s not too big to tackle in your own garage. Considering that this work can cost $500.00 or more at a shop, you can save over 80% of that expense by doing it yourself.

There are basically three types of rear main seal: a solid neoprene or rubber compound ring, a two piece ring of the same materials, or a rope impregnated with graphite, all of which go around the rear of the crankshaft, behind the last Journal. All are accessed on the rear of the engine block, behind the flywheel (manual transmission) or the flex plate (automatic transmission). In most cases, you won’t even have to remove the engine, just detach the transmission and shift the components using a jack and jack stands.

The best instructions I have found for tackling this procedure are at: ; there are also some good videos of this repair on YouTube; type in Rear Main Seal in the search box, and watch a couple in order to find the one best suited to your application.

I cannot emphasize enough that you should watch the videos and review the instructions as many times as necessary to become familiar and comfortable with the replacement process!

Of course, the best situation is that you never have to replace a difficult component like this during your life with this vehicle; this outcome is best achieved by proper maintenance, and that means staying within recommendations on oil and coolant changes most importantly!

Learn something new and enjoy!

Leave a Comment

Previous post: