rear main seal

[CobraCurtis]

Hey Keith,

First a little history: Your company built me a 408 Stroker and I am really happy and impressed with the quality of the parts and attention to detail when it was delivered back in 2005. I purchased it through Wayne Presley of Very Cool Parts and your mechanics installed his stack injection unit for me. I believe Tony remembers the build.

I have had the oil pan gasket changed twice now but am suspecting that I actually have a rear main seal leak. I know your warranty explicity excludes this item from warranty and I am not questioning that. But my question is how can I determine if my block is a pre-74 block and whether you guys installed a 2-piece seal? And from your experience, can a 2-piece seal be changed without having to remove the engine?

Curtis

[Rwillia4]

I've got the same problem!

[CoupedUp]

After 3,000 miles I think I have the same on my 427W. At first thought it was the oil pan, but now it's looking a little worse. Got to get her up in the air tomorrow and take a better look... Damn thing runs GREAT though!

Doug

[Rwillia4]

Someone told me that there is a "pill" you can put in the oil that will cause the seal to swell up and close. Anyone ever heard of it or used it?

Blows me away that with the big $$ can't buy a decent rear seal.

[bobcowan]

To find the year of the block, look on the block just above the starter. You'll find a number cast into the block. That will give you the year of the block.

In a SBF, any small oil leak will show up on the block plate. They all look like a pan gasket or rear main seal leak. One of the mechanics I know has a smoke machine designed to find the leak. He plugs it into a hole in the valve cover, and injects a petroleum based smoke into the crank case. Whereever you see the smoke come out is where the leak is.

I had a leak that I thought was a pan gasket. Turned out to be the fuel pump block off plate.

Whatever your local mechanic charges you to do this test is well worth it.

[CoupedUp]

Originally Posted by CoupedUp

After 3,000 miles I think I have the same on my 427W. At first thought it was the oil pan, but now it's looking a little worse. Got to get her up in the air tomorrow and take a better look... Damn thing runs GREAT though!

Doug

Just an update on my prior note above... Had a chance to do some more looking under the car. It appears to be leaking at the front corners of the oil pan. On both front corners of the pan, the gasket "squishes out" a bit and is soaking wet with oil. It is apparently running back along that line to the back of the pan and then blowing back onto the block plate, tranny, etc. I could find no oil anywhere above the oil pan, so I think that's it.

Doug

[RedBarchetta]

Hey, Doug. I've got my pan out right now as well (for a different reason). Hey, send it out for a powder coat while you have it apart (mine is at Embee right now...should get it back on Thurs).

Call me if you want to discuss.

-Deano

[CoupedUp]

Dean,
Mine already has a very nice ceramic coating on it that I paid dearly for. I'm going to be very careful not to scratch it! Good luck with whatever you have going on...

Thanks!
Doug

[ng8264723]

I powdercoat stuff myself. I paid $20 for an old oven. $10 for cleaning supplies wiped it down and put it on self clean for the inside. I paid $140? (thereabouts) for a Caswell powder coating gun and went to town. There is a small learing curve but boy is it nice to do your own parts. I coated everthing that i could unbolt from my 1991 Chevy truck underhood including the aircleaner. I blasted everthing and coated it. It all came out great. Perhaps not show quality but real nice. The more you do the better you get.
The manifold would of been $75/100 alone. I did every pulley everbracket the engine cooling fan. All with $20 worth of powder. I recently started coating my Jag suspension pieces from one of my other cars. I did the front control arms and they look great.

[pmfranke]

how does the home powder coat hold up?

[pmfranke]

can the pre 74 split seals be replaced without removal of the crank ? Another leaky 351.

[ng8264723]

Just as good as the industrial version. It's the same stuff

[reed1951]

Originally Posted by Rwillia4

I've got the same problem!

Is this a common thing with 408 strokers?!?

[Barnsnake]

The two piece seal can be changed by dropping the pan and the rear main cap.

[McD00]

Originally Posted by Barnsnake

The two piece seal can be changed by dropping the pan and the rear main cap.

If you loosen all the main caps the crank will drop slightly allowing the upper part of the main seal to slide in much easier. I have a pit at home so I just drive the car over it and crawl down in...real nice to work in...cooler too.

McVette

[Keithc8]

For about the last three years or so we have been using a one peice rear main seal in the 351W block that were two peice. We machine the blocks for the one peice seal to try and eliminate the rear main seals problems. I know that on a lot of the Superformance we have had the front oil pressure line leak at the block and run back. Remember any leak you have will run back to the center of the trans cover and look like a rear main leak. Double check all oil pan bolts as well along with any drain pliugs or fittings. Good luck, Keith Craft

[reed1951]

Thanks for that info Keith. I was actually going to ask you how you guys stop the rear main seal leaks because I had read in some threads where it was a common problem with 351w engines...and no one wants a leaky 7-10k engine lol. Since you started doing the one peice rear main seal machining have you had anymore complaints about the rear main seal leaking or has it basicaly eliminated it all together?

[McD00]

Originally Posted by Keithc8

I know that on a lot of the Superformance we have had the front oil pressure line leak at the block and run back. Remember any leak you have will run back to the center of the trans cover and look like a rear main leak. Double check all oil pan bolts as well along with any drain pliugs or fittings. Good luck, Keith Craft

Boy I hear that. The superformance oil line is a unique size. I got a fitting from Dynamic Motorsports that you push the line in and it holds like a chinese finger type thing. That fixed the leak for good. I think the fitting was $9.00 and worth every penny.

I'm just sorry I traded my car for a new roof on my house. Big mistake...

McVette

[Great Asp]

Originally Posted by McD00

Boy I hear that. The superformance oil line is a unique size. I got a fitting from Dynamic Motorsports that you push the line in and it holds like a chinese finger type thing. That fixed the leak for good. I think the fitting was $9.00 and worth every penny.

I'm just sorry I traded my car for a new roof on my house. Big mistake...

McVette

Bill,
Craig Hill used to sell the fix for this. (http://www.topofthehillpc.com/)

A braided SS AN line from the standard SPF gage to the block, replaces the plastic line and ferrule. Nice little kit, goes on in a couple of hours if you don't mind being upside down in the drivers set.

It was $90 bucks 4 years ago.

E

[McDoo]

Bill,
Craig Hill used to sell the fix for this. (http://www.topofthehillpc.com/)

A braided SS AN line from the standard SPF gage to the block, replaces the plastic line and ferrule. Nice little kit, goes on in a couple of hours if you don't mind being upside down in the drivers set.

It was $90 bucks 4 years ago.


Eric,

This is me...lol

I had Craig Hill replace the plastic line with braided line
and replace all of the fittings while it was in his shop
for 14 months and that is the best fix I have seen todate.
Craig has all of the correct threaded parts for the oil pressure gauge as well but nothing Craig sells is cheap
but you get what you pay for.

McDoo the REAL one...