Leaky Rear Main

[inviolet]

HAPPY NEW YEAR TO ALL!!!!!

I contemplating changing my rear main on my 383 again........I've done it twice so far with no success. The last time was better than the time before, so I guess my skills are improving........

Last time I used 2 FLATOUT - B/RB Hemi "All Season" Oil Pan Gasket .100" and a MRE - Billet Rear Main Seal Retainer and a bottle of Right Stuff Gasket sealer.

The FLATOUT Gaskets are awesome and seal excellent...IT'S the rear main that gives me a headache.....Any suggestions??? 

[Moparal]

sometimes on a crank shaft, the seal end is worn down. did you inspect the crank?  If your thrust bearing journal is worn too much, the crankshaft travels enough to cause a leak. It can also cause cylinder out of roundness and excessive ring bore ware.

The wide part of the seal faces in.  some people install the halves on different angles in the block and retainer, but that really never is an issue. clean accepter grooves are, A dabb of silocone in the bottom of the receptors snugs it inplace, a dab in the corners of the seal edges, a dab on both retainer end bottoms, fill the side wells solid on the retainer side walls to level and smooth. This would be done after you have tq'ed down the retainer.  If the engine was line honed or line bored, the retainer will be a bit longer to.

There may be other things someone else may suggest.  But also the crank case ventilation has to be good or wind will blow out the seal, push up dip sticks, blowq out front seal and things of the sort. To much oil in the pan will cause the engine oil to build up and ride all the way into 7 and 8 cylinder bores on excelleration to

[72cudamaan]

Are you sure it's the rear main?  Maybe the cam plug or pipe plugs are leaking a bit. 

[vinb]

Are you sure it's the rear main?  Maybe the cam plug or pipe plugs are leaking a bit. 

  Excellent point, alot of people over look those...

[lahatte]

I think if you have an older engine build, and it is worn and has blow by, then you may never get a seal to hold.  I've heard such, anyway.

[Chryco Psycho]

difficult area to seal up , typicaly I have found the side of the seal plate is the issue , I run a bead of Right stuff into the corner between the block & seal plate with a thin screwdriver

[Cooter]

Rear mains leak on Mopars, Chevies, Ford's, etc. with Two piece rear main seals...Don't believe me? Well, after you have done that rear main about 10 more times, you'll get the idea...You can slow it down to a drip here and there, but will NEVER stop leaking...

[Moparal]

   Mine don't leak.  It's all in the prep.  I will admit I am not batting 1000, but pretty darn close.   You can't race at a track with any leaks.  Dot your eyes, cross your tees , check , check, and recheck.  Once a problem is diagnosed, the problem can be fixed.

[72cudamaan]

I agree with Al.  Prep time and patience will seal any rear main if everything is within specs.

Hey Cooter, maybe you should try that spray on sealer.   

[Cooter]

Yeah,yeah,Yeah....I've pulled the rear main seal out of "Christine"(1966 440) about 6 times..The first time it was leaving a puddle on the ground about 10" round within 10 min. idling time...Right off the engine stand...Went in great, no problems...Each time I'm doing this, I run a bead of silicone up the side of that aluminum piece to be SURE it isn't gonna leak there..

Second time, seal lasted about 2 days, then was leaking about a 3" spot..
Third time, seal lasted about a week....Then, came the spots...
Fourth time, seal came from different vendor, didn't even get out the bay and was POURING OIL ...

Fifth time, back to the original vendor (Vendor said this was the last time they'd "warranty" the seal), about 3 weeks and seal was putting a couple drips on the bellhousing...(I've checked the valve covers, IT AIN'T THESE leaking as most everybody tells me it is)...Even thought it was that "Wafer" behind the cam..Pulled it, swapped it out with sealer round the edge, checked all the pipe/galley plugs...

Sixth Time and final time to date, installed another different brand seal. Seal is still putting drips on the ground and I've done everything I know to do with it cept swapping out the crank and that just ain't happening...

[mopar12372]

the mancini racing bilit rear main seal kit will correct this.

[Belgium Cuda]

When I had started up my stroker for the charger I had oil on the floor at that spot and thought it was the rear mainseal. It turned out to be the sendingunit for the
oilpressuregauge. Just to confirm what's have been said earlier that it can be other reasons.

Per

[moper]

Most cranks, including all factory, and most aftermarket new, have knurled main seal areas. Lip seals can have issues sealing on that under heavy abuse. I run rope seals on them if they have knurled seal areas. They take a little tiny amount of power away, but you will not have a leak, seap, or drip. Ever.

[inviolet]

the mancini racing bilit rear main seal kit will correct this.

I already have the Mancini Racing Built rear main seal kit and no luck..Still drips. I think Cooter has a point.

Any one have a picture of the back of the 383 Block so I can see where about these cam plugs or pipe plugs are? Hard to see with the Trany in place.............

[mopar12372]

 WAS ANY SEALANT USED?