Rear Main Seal

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mpbsr

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I think my rear main seal is leaking...not bad....but it is as I saw a few very lite drops of oil on the garage floor after pulling her in.

What really gets me is that the engine and trans were rebuilt about 5 years ago and I only drive about 1,000 miles a year. Guess I could leave it alone and check the oil level whenever I take her out and put her back in the garage.

Or, before it gets worse and I need to bring it into a shop to fix, any idea what the cost would be as I know it's not a easy job or cheap?

302 C4.

Thanks

 

Don C

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I would check the rear of the intake manifold gasket, the rebuilder likely stuck the cork gaskets on. Also the valve cover gaskets, due to the angle leaks migrate to the rear and then down the back of the block.

 

mpbsr

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UPDATE....Sort of

Took a deep breath and started doing some research on rear main seal leaks.

One possibility is the valve cover leaking and not the rear main seal.

I know my drivers side nearer to the firewall wall valve cover does have a slight leak. Now I did have Christine out today for a belated Mustang Day cruise and did 230 miles. 

So before I do anything else with the Rear Main Seal, going to change that valve cover gasket.

Can anyone recommend the best gasket to buy?

Cross your fingers and hope for the best.

 
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trillizo_y_uno

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Get a set of FelPro 1682 silicon valve cover gaskets.  You can remove and replace your valve covers at will and those gaskets just keep on trucking.  They are also very forgiving if your mating surfaces aren't true.  The only downside is the price.  I think a set will run you around $70.

 
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Valve cover gasket; I have had good luck with the rubber type with a metal reinforcement insert , Rock Auto list them for the 302. Mahle has one. Fel-Pro list the rubber, but I don't think it is reinforced. Check out R/A.

 

mpbsr

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Ron Tanzi

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1972 Ford Mustang Mach 1 bright red, standard black interior,pb,ps
gauge package.rim blow steering wheel,15" magnum 500s,351 C 2bbl running a 4bbl Holley 600,MSD 6a with stock distributor and Pertronix,Comp cam mild grind, The Engine(rebuilt by me in 2002 for the second time the first rebuild I did was stock in 1995) made 305hp and 358 lb ft on the dyno. 9" 2.75 rear end,Global west sub frame connectors,620 front coils.Rear defroster. My parents bought my car brand new the year before I was born. I cherish it like my child.
Get a set of FelPro 1682 silicon valve cover gaskets.  You can remove and replace your valve covers at will and those gaskets just keep on trucking.  They are also very forgiving if your mating surfaces aren't true.  The only downside is the price.  I think a set will run you around $70.
Are using the Fel Pro 1682 VC gaskets with the stock stamped steel valve covers? Summit states that they may not work with stock covers. I would love to use them on my engine if possible. You are correct they are pricey. Happy new year!! Thanks, Ron 

 

trillizo_y_uno

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Are using the Fel Pro 1682 VC gaskets with the stock stamped steel valve covers? Summit states that they may not work with stock covers. I would love to use them on my engine if possible. You are correct they are pricey. Happy new year!! Thanks, Ron 
Actually I am using them with a set of Boss 351 valve covers.  No idea if there would be any issues with the stock 351C valve covers.

 

Ron Tanzi

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gauge package.rim blow steering wheel,15" magnum 500s,351 C 2bbl running a 4bbl Holley 600,MSD 6a with stock distributor and Pertronix,Comp cam mild grind, The Engine(rebuilt by me in 2002 for the second time the first rebuild I did was stock in 1995) made 305hp and 358 lb ft on the dyno. 9" 2.75 rear end,Global west sub frame connectors,620 front coils.Rear defroster. My parents bought my car brand new the year before I was born. I cherish it like my child.
Actually I am using them with a set of Boss 351 valve covers.  No idea if there would be any issues with the stock 351C valve covers.
Thank you for that information. From what I know about the aluminum Boss valve covers is that the sealing flange is flat as opposed to the stamped steel covers which has a gasket retention lip.  I guess there is no way to know if the 1682 gaskets would fit unless someone out there has tried it. 

Best, Ron

 

Ron Tanzi

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1972 Ford Mustang Mach 1 bright red, standard black interior,pb,ps
gauge package.rim blow steering wheel,15" magnum 500s,351 C 2bbl running a 4bbl Holley 600,MSD 6a with stock distributor and Pertronix,Comp cam mild grind, The Engine(rebuilt by me in 2002 for the second time the first rebuild I did was stock in 1995) made 305hp and 358 lb ft on the dyno. 9" 2.75 rear end,Global west sub frame connectors,620 front coils.Rear defroster. My parents bought my car brand new the year before I was born. I cherish it like my child.
Thank you for that information. From what I know about the aluminum Boss valve covers is that the sealing flange is flat as opposed to the stamped steel covers which has a gasket retention lip.  I guess there is no way to know if the 1682 gaskets would fit unless someone out there has tried it. 

Best, Ron
Correction, I got it wrong on the Cleveland stamped steel valve covers having a gasket retention lip. They are indeed flat like the Boss aluminum covers. I had just done a set of VC gaskets on a 69 Dodge 383 recently (which have a flange with a lip the gasket fits into). My brain is burned out from 2020 I guess. I am going to give the 1682 gaskets a shot. After action report to follow. Just don't know when. 

Ron

 
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