C1 Rear Main Seal

[Michael K.]

What is the best rear main seal available for my 57 283? The car has had a leak at the rear of the engine forever. I have tried rope seals and rubber seals.

[Roy B.]

Re: C1 Rear Main Seal

Original rope seal if it's installed right.

[Michael K.]

Re: C1 Rear Main Seal

Who would have the best rubber seal?

[Roy B.]

Re: C1 Rear Main Seal

Well C&C has them

[Michael K.]

Re: C1 Rear Main Seal

Corvette Central?

[John H.]

Re: C1 Rear Main Seal

Paragon has the wire-reinforced rubber replacement seal too - I used one on my '57 when I restored it back in '96, never leaked a drop.

[Rob Dame]

Re: C1 Rear Main Seal

I also used the wire-reinforced rubber seal on my 56 four years ago now. It has never leaked since. Make sure you seal the corners of the bearing cap like the instruction tell you to. I also mis-aligned the seal seams to the seam where the bearing cap meets the block just a tad.
Rob

[Michael K.]

Re: C1 Rear Main Seal

Rob, you said that 'misaligned' the seams. I am assuming that one end of the seal is sticking out of the block while the other end is pushed in. The benefit being the seam on either end is surrounded by the block or cap groove.

[Rob Dame]

Re: C1 Rear Main Seal

Correct and it doesn't take much...maybe 1/8" Rob

[Jim T.]

Re: C1 Rear Main Seal

Another two piece rear seal from GM is #10121044. This seal is made to tolerate higher engine temperatures and has more face pressure. It is listed in the 2003 GM Performance Catalog as a seal used by most NASCAR Teams. It can be used in V6 and V8's.

[Joe L.]

Re: C1 Rear Main Seal

Jim----

The 10121044 seal is now the SERVICE rear seal for all 1959 to 1985 small block applications. However, it cannot be used for 1955-58 small blocks which originally used a "rope" packing (seal). For those applications, a special "conversion" seal is necessary. GM does not offer such a seal, but it is available in the aftermarket.

[Jim Callan]

Re: C1 Rear Main Seal

Does this require a "special" sealant or RTV be used ?

Thanks

[Jim T.]

Re: C1 Rear Main Seal

Joe thanks for the years of application for the seal. The 2003 GM Performance Parts book did not supply this information. Plan to use this seal on my 85 with a one piece oil pan gasket.

[Joe L.]

Re: C1 Rear Main Seal

Jim-----

I used to use Indian Head for the rear main seal adjoining areas that MUST be treated with sealant. However, I use Permatex Ultra Copper now. It must be applied to the areas shown on the instruction sheet that comes with the seal or as shown in later editions of the Chevrolet or Corvette Service Manuals. The application of the sealer to the instructed area is absolutely critical. You WILL have a leak if you fail to do it.

[Jim Callan]

Re: C1 Rear Main Seal

Thanks Joe,, I'm thinking of the rear bearing cap that contains the "seal", I thought a special sealant was required where the 2 pieces joined. A sealant that only cured in the 'absense' of air, it's kinda fuzzy.

Thanks