Rear main seal - lifespan??

jswilson64 · Jun 1, 2003

Short story/question: How many miles should a rear crank seal last on a '96 Odyssey (140,000 miles)?

Here's the (long) story. Had the front crank seal, balancer shaft seals, new timing belt, water pump, and the (cracked) oil pan replaced in March to fix oil leaks at the front of the engine, by "Repair Shop A." Since then, I've noticed a few drips of oil, maybe a drop when it was parked, nothing serious-looking. Just in the last week or so, there has been an increase in the amount of oil on the garage floor.

So I took it to my Honda mechanic ("Repair Shop B") for slightly-late 120,000 mile service, and to check out the leak. They looked it over for quite a while, and said that it's either the oil pan seal, or the rear crank seal. They can't be sure because of the location. There was one slightly-loose bolt on the oil pan that they tightened. They said that the best course is to have the oil pan seal/gasket replaced by the shop that replaced the pan. Then, if it keeps leaking, it's the rear crank seal.

He showed me where it was leaking, and it's right where the oil pan is closest to the transmission, but there is some kind of shield there, and they say the flywheel/torque converter, can be slinging the oil up so that it looks like the rear crank seal is leaking.

Also, he says we've got a "fair amount" of blow-by, and that could be causing the crank seals to fail by overpressurizing the crankcase.

So, again, my original question: Should the rear main seal last longer than 140k miles? Just trying to prepare myself for the bill if it's the rear seal. We've spent over $1200 in repairs in the last 6 months or so, and another $500-600 is going to hurt...

Thanks,
James Wilson
Dallas TX

accordian · Jun 1, 2003

Make sure the PCV valve is in good shape, put a new one to be sure. If it's bad it can cause extra pressure in the crankcase.

Can't the shop remove that shield from the end of tranny and clean things up a bit under there? I'd try cleaning it up as good as possible, drive it for 30 to 60 minutes, the get back under there again and take a look. If the engine side of the flywheel is steaked with oil, though, I'd suspect the rear main. I use brake cleaner to do this when I'm trying to find a leak.

However, if something was recently messed with, it's the first thing to suspect. In this case, that's the oil pan gasket. If you can't figure out where the leak is coming from, replace the oil pan gasket. It's best to eliminate the less expensive possible sources first.

moose · Jun 1, 2003

I have a leak in my main seal on my Acura Legend with 125,000 miles. Try the following, clean the engine, then have a dye put in the crankcase, it should take a few days but should help make it easy to more definitely locate the leak. A cheap solution my mechanic tried was to put a container of a product, I think it was called "stop leak" or something similar for $10, it was a small container, maybe 12 ounces or so. It is supposed to swell the gaskets as it leaks. I'll be dammed, but my leak over the past few weeks seems to have stopped. Certainly worth a try, it isn't supposed to clog like the stuff you put in the crankcase for a cracked head gasket, don't mix the two products up. He gave me the jar so I can do it at another oil change, if I locate the jar, I will post the exact name.

jswilson64 · Jun 2, 2003

accordian said:
Make sure the PCV valve is in good shape, put a new one to be sure. If it's bad it can cause extra pressure in the crankcase.

Can't the shop remove that shield from the end of tranny and clean things up a bit under there? I'd try cleaning it up as good as possible, drive it for 30 to 60 minutes, the get back under there again and take a look. If the engine side of the flywheel is steaked with oil, though, I'd suspect the rear main. I use brake cleaner to do this when I'm trying to find a leak.

This sounds like what my Honda shop did. They pulled everything they could without actually dropping the oil pan, drove it around the block a couple of times.

accordian said:
However, if something was recently messed with, it's the first thing to suspect. In this case, that's the oil pan gasket. If you can't figure out where the leak is coming from, replace the oil pan gasket. It's best to eliminate the less expensive possible sources first.

I agree. The guys at the Honda shop I went to seemed genuinely troubled that they couldn't be sure what it was. it's going back to the "other" shop to have the oil pan re-done, and we'll see where we're at. Maybe I'll have them put on a new PCV valve, too, just to make sure of that, although it should have had a new one of those with my 120k service...

James Wilson, Dallas, TX

KartRacer · Jun 2, 2003

A trick for finding a source of a leak is to clean the whole area where you suspect the leak is coming from. Then put a really LIGHT coat of oil with a rag and then put baby powder over the whole area. That should help trace the leak to it's source

Jerry O · Jun 4, 2003

KartRacer said:
A trick for finding a source of a leak is to clean the whole area where you suspect the leak is coming from. Then put a really LIGHT coat of oil with a rag and then put baby powder over the whole area. That should help trace the leak to it's source

Would that work on a baby, too?:stupid:

Jerry O.

accordian · Jun 4, 2003

:rotfl: Never had trouble finding the source of the "leak" on my babies! Now getting them to stop "leaking," that was another story.

Jimhondaowner · Jun 19, 2018

engine main seal leaking - As for engine additives. I have a 2003 Honda Odyssey with a leaking engine main seal to the transmission. The Odyssey now has 152000 miles, transmission was replaced by Honda (the tranmission was free from Honda, I paid the labor) and replaced the main seal @ 77,000 miles. We put in a new engine mail seal again @ 130,000. I did not want to do this again as it cost in the neighborhood of $800 so with advise on line I used ATP Re-Seal, 8 oz. (AT205) for about $15. Drove 500 miles on and off. And put the van on a lift saw no leaks, wiped the area, and lifted it again for tire rotation in another 250 miles and it was still dry. I can say it worked for me, and I am impressed. I hope this helps someone else.

Rear main seal - lifespan??

jswilson64

accordian

moose

jswilson64

KartRacer

Jerry O

accordian

Jimhondaowner

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