Planning on trying to do a rear main seal soon

[69wannabe]

Every since I went from my stock stroke 440 to the 493 that i'm running now I have had a rear main seal leak. It was really bad at first and I had it out and apart a few times before finally going to a rope seal and it's been like that for a few years now and it's not a bad leak but it drips and it bugs me. I am going to try something different this time that I read in a message from Ron (firefighter) that had a link with a similar problem. I need to do a repaint on the engine anyway since it's looking really crappy. I'm thinking of maybe upgrading to some aluminum heads and an aluminum water pump housing to lighten up the engine some and help it breath a little better. Hoping to at least get rid of my annoying oil leak.

I have a jeep 6 cyl to put together before I pull the engine on the charger. I have almost got the parts together to start putting the bottom end together and I had to buy a reman head since the other one was cracked. Still got to get main bearings and a timing set and a few other things and the 4.0 will be going back in hopefully!!

[A383Wing]

I'm running the neoprene rubber lip seals in all my rebuilds...no leaks ever

[69wannabe]

I have always ran the rubber lip seal in all the big block rebuilds that I have done and this one leaked. I tried three different ones before I went to the old rope seal. Planning on following the directions from the link that was sent to me. Going to mill some off of the #5 main cap closer to the rear seal retainer to open up some room between the cap and the retainer. Going to put the gaps of the seal at 12 and 6 o clock instead of even with the block and cap. This is what fixed the one in the link that was doing the same as mine is doing. By putting the gaps at 12 and 6 o clock this makes the retainer have to line up perfectly. It did say the retainer should line up easily and if it doesn't you may have to open the bolt holes up a little bit to make it go on without binding which seems like no big deal to me at all. Also going to install the anti-leak rear main bearing that is supposed to direct oil away from the retainer. Maybe this will take care of my oil leak!!!

[Bronzedodge]

Could it be the retainer side seals, instead of the main seal itself?  I've had trouble with those in the past.   

[69wannabe]

Could it be the retainer side seals, instead of the main seal itself?  I've had trouble with those in the past.   

I have used the side seals and I have done the silicone method too for the side seals. Honestly I don't really know exactly where it's leaking but it seems to be dripping directly off of the crankshaft in front of the flywheel. Really dreading pulling the engine back out but I really hate having an oil leak too....

[A383Wing]

could also be camshaft plug, oil gallery plug, or even the rear of the intake leaking and running down

[Challenger340]

The groove in the Block that holds the seal, is NOT concentric with the Crank centerline on a BB Mopar.

Therefore,
You have to put the Crank in the Block with the Seal installed flush with the parting line, and #5 Main Cap off, and then observe which side of the Lip Seal is NOT compressed against the Crank and Not sealing.
Then,
offset that "offending" side up about 1/2" from the parting line, offset the seal half in the retainer the same amount, then work the retainer down mated, and use a screwdriver lightly to wedge the retainer over to one side dragging the "offending"(not sealing) side into contact as you tighten the Bolts.
Seal the sides with silicone.

[69wannabe]

That is almost what the post in the other forum say's but they put the mating end's at 6 and 12 o clock and he said to do this with the crank out and see if the retainer lines up easily with the bolt holes and if it doesn't to open up the holes in the retainer a little bit until it goes on very easily. I just don't understand why it never leaked with the factory steel crankshaft in it and I had it in there for a few years until I decided to do the aftermarket crank and since then it has leaked at the rear main since. I even had the crankshaft sent and checked to make sure the sealing journal was true and it came back ok according to them. I will check this every way I can when I pull apart this time and hopefully have some success with it. I still have my factory rotating assembly but the 493 runs great and if I can get this oil leak fixed I plan on doing some better heads and a better exhaust system to maybe put me up to the 550 hp range.

[AKcharger]

Are you saying you have to remove the crank to change the rear main seal???

[69wannabe]

That is my plan, I want to get a real good look at everything back there just in case I am missing something somehow. Plus there is a rope seal in there at the moment that will be alot easier to remove if the crank shaft is out. Not a big deal really and the engine needs a good cleaning and repaint anyway. Haven't had the engine out of it for like 5 or 6 years so I guess it's due to be taken apart. Plus I got 4 boxes of that thermo tech heat and sound mat for the floorboards to put down too. Would love to do some stealth heads while I have the engine out but my budget may not allow that. My daughter has one more semester of college I have to pay for and she will graduate. After that is over I may get to get the heads and have them worked and mark that off the to do list. Would also like to do some really good 1 7/8" headers on there but I really would like to get some that fit without me having to beat them to death. I have the headman 1 3/4'' coated elite's on there now and they are ok but I think it would benefit from some bigger tube headers and maybe some 3'' exhaust. So many thing's to do and so little cash to do them!!!! Story of my life!!! LOL

[Windsor]

When I had my motor built, he was fighting the rear main seal to get it to stop leaking. Tried 4 (I think) new seals and two billet retainers. Finally got it to seal. That was after rechecking crank, groove in block, and retainers (which measured out to be identical).