426 hemi rear main seal

[terzmo]

426 hemi new 91 block with molnar crank. First seal leaked like a badly....second leaks but not as bad...crank is not knurled on the end,smooth.

Anyone have a sound suggestion ? Thanks B Bodies...Thanks in advance to all

 

[Meep-Meep]

Once the seal itself is installed correctly the seal retainer needs to be sealed along the sides of the block and the area around the bolt holes.

 

[Hemirunner]

Check to make sure the seal retainer is sitting flat on the block. Sometimes they hit the cap or the #5 main cap nuts. Make sure if you're using a new style seal in an old style cap that you remove the nubs that are there to 'bite' into the rope seal. Sometimes they distort the seal or open up a path around the seal.

 

[terzmo]

Bought a billet cap and seal kit from mancini...milled it about 12 thou...installed and no more leaks from the rear.....EXTREMELY HAPPY

 

[Acmerep]

Bought a billet cap and seal kit from mancini...milled it about 12 thou...installed and no more leaks from the rear.....EXTREMELY HAPPY

Why did ya mill the cap 12k ?

 

[terzmo]

Why did ya mill the cap 12k ?

snugger fit

 

[miller]

Also made it out-of-round.

If all else fails, put one of the older rope type seals in it.

 

[terzmo]

Also made it out-of-round.

If all else fails, put one of the older rope type seals in it.

I could care less about "out of round" tried every other option....this worked

 

[miller]

That's what counts, isn't it.

 

[terzmo]

That's what counts, isn't it.

I posted what I did successfully and people have the option to try it or not. I didn't post to get someone to bust my balls

 

[erickson]

I machined .010 off mine and it stopped the leak. Will being doing one more this weekend

 

[terzmo]

I machined .010 off mine and it stopped the leak. Will being doing one more this weekend

That's all I hoped would happen. My post helped and would like to hear about the second one.

 

[miller]

I posted what I did successfully and people have the option to try it or not. I didn't post to get someone to bust my balls

That is not why I made my comment. If it offended you, I'm sorry.

A critical leak like that...is because something isn't right. Especially with new parts! But, you've also got after market parts. There's always the chance the seal journal is undersized, or itself out-of-round.

Hell, I'll leave it at that.

 

[malex]

Recently finished a 505 and when it hit the dyno the rear seal leaked. Was surprized that it was leaking because it was installed properly, and it was well sealed up along the sides of the retainer with right stuff.. Once I got it back home I took another crack at it. The next time I installed the seal so that the ends were installed at the 6 and 12 oclock positions. Not at the block / retainer joints. With the seals installed at 6 and 12, they sit firmly together. Then I dropped the retainer over so that it would drop straight down over the seal without distorting the seal in any way. By doing this I found that the retainer would now come in contact with both the main cap and the rear main stud nuts. I clearanced the areas that I needed to on the retainer (stock retainer) so that when I dropped it over the seal and tightened it down it no longer touched the cap or main stud nuts. I removed it one last time, popped the rear seal out and applied a very slight touch of right stuff on the ends of the one seal, slide them back into the 6 and 12 oclock positions. Then I slipped the retainer over the seal again, making sure not to distort the seal in anyway, dropped the bolts in and torqued. Finished up with right stuff along the retainer/block edges. Reinstalled the girdle, pan and into the Plymouth. The 505 is bone dry underneath now.
I got the idea of installing the seal in this position from a post in Moparts. A fellow has been installing the rear seal in this manner for over 20 years without a leak.
I believe that my problem was that the first time the seal in the retainer half was not lining up evenly with the seal half in the block.
By installing the seal halves straight up and down, when you drop the retainer over it lines itself up to where it's got to be. Clearance where and if needed. It sure worked for me. No leaks, 720 HP & 677 TQ.