any trick to 5.0 rear main seal?

[Stangler]

When I did the C-4 swap, I changed the rear main seal. It leaked bad after!!! WTF!!! pulled it out (tranny) and found that it wasen't seated all the way, so I pushed it all the way in. Went for a drive,... and it leaks!!! WTFWTF!!! When I put it in, I lubed the inside and slipped it over the crank. Does it need RTV on the outside edge? anybody with ideas, I'm pulling the tranny again for the last time and want to fix it for good.

Nate

 

[tmoss]

Yes, use some rtv to seal the metal outer ring on the main seal.

 

[Matts89LX5.0]

good, eventually i was gonna ask the same question

 

[MusPuppis]

would the RTV trick work for the trannys main front seal? I replaced it last time I pulled the tranny out but its steadily dripped every since.

 

[Stalkerfiveo]

it seems as if once the stock seal goes bad youll bnever get one to last very long again.sad but true

 

[tmoss]

would the RTV trick work for the trannys main front seal? I replaced it last time I pulled the tranny out but its steadily dripped every since.

Yes it would.

 

[GT Trooper]

Good luck, I replaced mine twice and it still leaks.

 

[SWYZ721]

This was my concern when I was purchasing my stang, I was very worried until I spoke to one of my good buddy's friend, who told me in one season he dropped the trans 5 times and every time it seeped, he threw in every different seal teflon and what not, he said from his experience they all leak to some degree and it's mostly harmless. Just like the beatiful eaxhaust note, it's a 5.0 thing.

 

[tmoss]

Could be an indication of main bearing wear too. Movement will wear the seal out early and cause it to leak from day one it it's not running true. Consider that if your a high mileage car.

 

[Stangler]

It leaks enough to get oil thrown onto the exhaust by the flex plate, and that is what bugs me. Car sits at a light and you can see alittle smoke coming from under it. I'll be pulling it soon, and I'll try the RTV trick and let you guys know. I'm getting sick of pulling the tranny, but not much else going on

Nate

 

[Stang8URMPRT]

I've changed my rear main 3 times in about 5000 miles... All felpro seals... Every time I've done it, I used RTV... but it still leaked... Yet, that wasn't what was leaking. For those that don't know, your flywheel/flexplate to crank bolts can leak. The tapped holes in the back of the crank actually go all the way through, and if you do not use RTV or some type of thread sealer, you will get oil getting through the threads, making it look like a rear main. My two cents... And mine doesn't leak anymore.

Nick

 

[tmoss]

Yep, threads have to be sealed too.

 

[Stangler]

Yep, threads have to be sealed too.

I used red loctite, on the flexplate bolts. should I use RTV?

 

[tmoss]

Red loctite (permanent) will make getting the bolts out a bear, but it will seal the threads. Next time I'd use the blue loctite - kmeant to be disassembled but still hold well.

 

[Stangler]

Red loctite (permanent) will make getting the bolts out a bear, but it will seal the threads. Next time I'd use the blue loctite - kmeant to be disassembled but still hold well.

K.... maybe I did use blue? It's red in color, but in a blue tube!? (Not looking at the product at this moment, but remember the tube)

 

[tmoss]

Color of the fluid is waht counts - red is permanent and blue is meant for dissassembly.

 

[ratrapp]

also if the motor has alot of blowby it will push the seal out.thats what my motor does.

 

[tmoss]

blowby should be taken care of by the PCV system - be sure the PCV valve is new(er) and the filter screen below the PCV valve is not plugged up with gunk which is a very common thing. Don't try to clean one, they get deposits that most solvents won't touch - buy a new one for a few bucks.

 

[GT Trooper]

I've changed my rear main 3 times in about 5000 miles... All felpro seals... Every time I've done it, I used RTV... but it still leaked... Yet, that wasn't what was leaking. For those that don't know, your flywheel/flexplate to crank bolts can leak. The tapped holes in the back of the crank actually go all the way through, and if you do not use RTV or some type of thread sealer, you will get oil getting through the threads, making it look like a rear main. My two cents... And mine doesn't leak anymore.

Nick

I sure wish someone had told me this. Both times I failed to use a sealer on those bolts. I have no desire to go through this again but what the hell, it's winter time.

 

[HISSIN50]

so do you all recommend using a silicone type product (copper RTV, etc) or blue threadlock on the flywheel bolts? i usually use some threadlock, but would use RTV if the threadlock might not seal well enough and 'backing out' is not much of an issue.
TIA.