312 rear main seal
 

Can the rear main seal be replaced without pulling the engine?
Thanks

Re: 312 rear main seal
 

Yes, if you can get the pan off. You may need to drop the drag link. Also may need to rotate the crank to get the counterweights up out of the way of the pan unless you're really lucky.

Re: 312 rear main seal
 

I replaced the rear main on my 312 with the engine in place in my roadster. I used the Best Garket black neoprene seal, and followed the instructions by Ted Eaton. One caution, Best made some silicone seals that were orange, and they failed often under 500 miles. That's what I replaced. If you get one (and you shouldn't, they should all be gone) don't use it.

Ted's article

http://www.eatonbalancing.com/2008/0...-y-and-others/

Re: 312 rear main seal
 

Ok - thanks Guys...will give it a shot. Can’t leak any more than it does now! Thanks

Re: 312 rear main seal
 

Jake, my engine is probably 35 years since it had gaskets. I had several small leaks, enough to really upset me. I changed oil to mobile 1 and added 1 qt of Lucas stop leak, I also added a little of the transmission stop leak and a little power steering stop leak. That was a year ago and I drive the car often. Every now and then I see a drop. Getting oil leaks out of a 63 year old car is a task.
If the only leak you have is a rear main, then it would probably be a good idea to replace the rear seal.
Good luck

Wrong car, the car I was referring to, is a 1956 Ford Fairlane 292

Re: 312 rear main seal
 

If you still have the rope seal still you will need to get creative to remove it. Slightly loosen the main caps and make some little picks and needle nose pliers to remove. That's the hardest part. And as miker98038 stated use only the black colored "Best" Brand seal. I have found it best to slightly clock the new seal slightly when installing. Maybe 1/4-3/8" and either red silicone or Permatex "Right Stuff" on the cap mating surface. Silicone is okay as long as you aren't too messy. Clocking probably is not necessary but it helps seal the mating surface. Before installing the side rails put a little sealer in the groove first. The new seal should have a horn to help getting it started around the crank. I myself prefer Permatex.

Re: 312 rear main seal
 

I have seen more leaks at the holders mount than the actual seal. Make all the parts very clean, use lacquer thinner or acetone and Q Tips. The threads on the two bolts too. Use sealer very sparingly, but very accurately.

Re: 312 rear main seal
 

First I saw this tool I was 16. I'm 70, so it's been around for a while. Don's right about the seal retainer.

Look at Ted's site about offsetting the seal. I linked it above.

https://www.amazon.com/Lisle-27000-S.../dp/B0002SRCJW

Re: 312 rear main seal
 

[QUOTE=Ole Don;1845606]I have seen more leaks at the holders mount than the actual seal. Make all the parts very clean, use lacquer thinner or acetone and Q Tips. The threads on the two bolts too. Use sealer very sparingly, but very accurately.[/QUOTE

On a 312 don't rule out a cracked block either.

Re: 312 rear main seal
 

This post is based on the assumption that where oil seal retainer meets the engine block contributes to leakage at the points of contact, between the block and the retainer this might not get a proper seal
. Would it help to cut the rope seal that goes in the block short and the rope seal that goes in the retainer long so the seam of the rope seal would higher than the contact points of the block and the retainer.
just a thought while I was assembling the engine. A person could put one part of contacts points on the seal staggered which might help slow down the leak.
Let me know what you think. Larry

Re: 312 rear main seal
 

Ted Eaton’s article I linked above discusses that, with pictures. Read it carefully and avoid most problems.