57 312 yblock

[zetterberg]

I have a rear seal engine leak. Is there anything I can use to stop it  without replacing the seal.  Thanks

[Ford_Crazy]

Depends upon how bad it is.  If you've tried stop leak and all the usual canned cures, you will most likely need to replace the seal.  There are kits you can buy that will allow you to change the seal without disassembling the engine.  I have used them a couple of times, and while not a piece of cake, they do work.  The kit comes with a "Chinese finger" which is a hollow rope made of steel mesh.  You drop the pan and the rear main cap, knock out the old seal and thread the tool around the crank.  The tool holds the new rope seal and you pull it into position around the crank.  It works, but it's not for the average weekend mechanic.  You'll need a lot of patience.  312s are getting rare and are worth keeping and rebuilding these days. If it was me, I would leave it alone unless the oil is running all over the place. If that's the case, personally I would go through the engine. Dripping seals are part of the Y-Block experience. 

[JimNolan]

zetterberg,
    What Ford_Crazy said is true ( except for stop leak, I don't know about that ). The procedure for installing the rope rear crank seal in a Y-block after the engine is installed is an art form all to itself. Years ago ( 1970 ) I rebuilt a Y-block and just placed the seal inside the bearing caps and cut it to length. It leaked like a seive. I inquired how to fix it around town ( Blacksburg, Va ) and the car company told me I had to take it to Jiles County to a man that raced Y-blocks ( back then Y-Blocks ruled the dirt track ). They said he was the only guy that could make them hold in that part of the country. I took it to him, left it for a day and when I picked it back up that evening it never leaked again. The guy told me me what he'd done. You have to pack a rope seal. He dropped the crank far enough to get the old seal out and install a new one. He then used some form of rod to keep pushing on the seal and pack it into place.
   My advice to you is to send a personal message to Hoosier Hurricane and see if he'll inlighten you on how to keep your Y-block rear seal from leaking. If anyone knows it would be someone that raced them and rebuilt them all the time. Jim

[Hoosier Hurricane]

The last seal I installed in my 312 Bird, in the car, was the Best Gaskets orange seal, I think it is silicone rubber from the look.  Anyway, it's a lip seal, not a rope.  No leak, it installs much easier than a rope.  Best now has a teflon rope seal available, I have not heard any reports about it.

An old trick I have used in the past with the rope seal is to round off the end of a 1/16" gas welding rod, drive it around the backside of the upper rope to swell it a little, cut the tips of the welding rod flush, install a new bottom half of the seal.  If the main bearing is worn, it should be replaced to keep the crankshaft centered in the seal.  And now for the bad news on new rope seals.  They no longer have asbestos in them, they are a synthetic fiber (maybe dacron?), and they do not seal the oil, rather they act as a wick.  I had a comeback (actually a "never leave") on a '57 Bird overhaul with the new rope.  Dug the old one out of the trash, wired the backside and the cap side, put it back in.  No leak for several years.   John

[zetterberg]

Thanks for the help.

[alvin stadel]

I'v got 3, 312's with the new type silcone rubber seal that Ford Crazy is talking about and I think they work great, I still have a little leak on one of them, my 57 bird, but nothing to complane about. I give up on the rope seals a long time ago, I hate oil leaks, but then sometimes I think Y-blocks are like detroit  diesels and were made to leak.

[shopratwoody]

Alvin
The Detroit Diesel thing is funny. Had both. Have had a couple
dry ones thpugh