Engine Rear main seal keep leaking, second attempt

Swhitney

Member
Feb 11, 2019
92
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Oregon City
I know this has been widely talked about, but I am really struggling to fix the glitch.

I have a 1992 mustang with a 347 stroker. I had recently replaced the rear main seal when the engine was out when I was doing engine bay cleanup. The problem is she continues to slowly drip oil. I then pulled the tranny and install the felpro seal savor with a new seal, and yet again she continues to leak. I used blue loctite on the flywheel bolts, and am running the stock PCV valve with vented valve covers. What else should I do to stop this silly leak?
 
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mcowing

Member
Jun 6, 2010
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I'm the same with a stock 5L. Brand new seal still drips. I read someone in a forum once say with these cars even Ford considers a slight drip within the range of 'normal'
I also read you're supposed to use thread sealer (not thread locker) on the flywheel bolts.
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
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I read where the seal saver needs to be installed with red loctite or it will leak between it and the crank.....
 

Swhitney

Member
Feb 11, 2019
92
3
18
Oregon City
I read where the seal saver needs to be installed with red loctite or it will leak between it and the crank.....

Yeah I'm hearing that same thing now. I will most likely pull the seal savor and install a new one with green loctite.

There needs to be a full prof way for these things not to leak. When I installed the first one there was no oil pan getting the way so I know that I didn't damage it. Even the 2nd one seems very tight on the seal savor. I assume it could be leaking from around the seal savor or coming out of the fly wheel bolts?
 

Specracer

Member
Nov 24, 2020
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SE MA
I did the redi sleeve with locktite (blue), but used black RTV on the flywheel botls. Have not put many miles on it, but so far so good.
 
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limp

wrap a little cheese around it and its a done
Oct 4, 2020
608
282
73
66
Florida
I did the redi sleeve with locktite (blue), but used black RTV on the flywheel botls. Have not put many miles on it, but so far so good.
I have been toying with using ARP thread sealer on the flywheel bolts..
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
608
282
73
66
Florida
I did the redi sleeve with locktite (blue), but used black RTV on the flywheel botls. Have not put many miles on it, but so far so good.
I just purchased a sleeve and tool ( man what a gimmick) and it says to put non hardening sealer on the sleeve before installing it... So, not sure to use loktite or non hardening sealer.....
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
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Massachusetts
I bought the tool on Amazon. After the install there was no noticeable indication I used it, so I returned it. Consider it Amazon rent-a-tool. ;)

You can use anaerobic flange sealant like what you should use on the T5. Just a tiny bit
 
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Swhitney

Member
Feb 11, 2019
92
3
18
Oregon City
I bought the tool on Amazon. After the install there was no noticeable indication I used it, so I returned it. Consider it Amazon rent-a-tool. ;)

You can use anaerobic flange sealant like what you should use on the T5. Just a tiny bit
I bought the tool, but kept it.
what sealant are you putting on the T5?
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
12,091
224
Massachusetts
Loctite 518 for transmissions and rear axles


Loctite 515 would probably be more appropriate for the sleeve here. However in reading up on these sealers not sure it's the appropriate application as they do harden up.
 

Swhitney

Member
Feb 11, 2019
92
3
18
Oregon City
Loctite 518 for transmissions and rear axles


Loctite 515 would probably be more appropriate for the sleeve here. However in reading up on these sealers not sure it's the appropriate application as they do harden up.

I bought some Loctite 290 to smear on the inside of the seal savor. The rear main I plan on using a small amount of RTV silicone on the outside, and RTV on the flywheel bolts.
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
608
282
73
66
Florida
Loctite 518 for transmissions and rear axles


Loctite 515 would probably be more appropriate for the sleeve here. However in reading up on these sealers not sure it's the appropriate application as they do harden up.
Are you saying the 515 might be the wrong stuff?
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
12,091
224
Massachusetts
Are you saying the 515 might be the wrong stuff?

Both 518 and 515. I've trying to research the applications.

518 is great for rear ends and transmissions. It works very well against oils. 515 is the same but doesn't work well with aluminum. Both harden however in the absence of oxygen, which is why i am questioning if this is the right application for it

I have a tube of 518 on my shelf. I probably would have just used it.

EDIT: everything i'm reading seems to suggest 518 is ok. 518 has a higher temp rating than 515 but 515 sets faster. Both are rated to fill a gap up to 0.01" which shouldn't be an issue for a sleeve
 
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