how to prevent rear main seal leaks

[chubbyranger]

Originally Posted by tateos

Two suggestions:

Do not overfill the crankcase - in fact keep it closer to the ADD mark than the FULL mark. This will help keep the crankcase pressure down

Also, don't do what I did and switch to synthetic oil on a high mileage motor - they syn oil dissolves all the crud (however minor) that exists on the surfaces and it will cause leaks to appear that were never there before. I had read that advice many times, and when I didn't heed it and made the mistake of switching to syn oil, I learned it was true - at least for me.

Richard Moore

I switched my car to synthetic at 87,000 miles 10,000 miles ago and still don't have any leaks. (knock emos - )

[derone]

Not sure if northstars have issues with blown rear main seals, but I've seen a `90s SBC push one out after the PCV system got stopped up. Mine had what looked like a rear main leak but was really the oil pan gasket. The oil dripped from the eng-trans bracket/exhaust pipe shield which is right below the seal. It's as clean as a pin under there now after $1100 to fix it.
Doug

[tateos]

I am in the middle of a HG job right now - I plan to change the rear main seal and the oil pan gaskets, as well as anywhere else that could be leaking - that includes the oil level sensor and front seal. The case half seal looks OK, and I don't want to mess with that if I don't have to; I heard you need to put in new bearings and oil distribution plate if they are disturbed, and I think that part of the engine is OK.

RM

[eldorado 2000]

I know of no "fix" other than replacement when the leak. After driving hundreds of thousands of thousands of miles, NEVER had a rear seal leak. Only ever replaced one in my life and that was on a Dodge Magnum 440 with a 6 pack -- and only when the motor was rebuilt.

[iametarq]

Apparently my rear main seal is leaking. But I'm skeptical. I have always had a bit of oil on the bottom of the car, and every 4,000 miles or so I'll get "check oil level" and it's when the engine oil life shows at 50-55% left and that is when i change the oil anyway. This time the guy says it was 'saturated'.

I should add that it has never, ever left any trace on pavement though. I'm not super worried. I'll just make sure it's always between full and fill on the dip stick.

[adamh21]

I think my RMS is leaking. I'm not sure but there seems to be a bunch of something on the ground, I haven't investigated too seriously as of yet, I just figure...It leaks, I refill it, what could possibly go wrong...right?

haha

[iametarq]

as long as I keep on top of mine, I think I'll be fine. The losing a quart is pretty on par with what is already documented here in the tech tips section.