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440 Rear Seal problems

appleby66

appleby66

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Just had a 440ci bracket engine built and had it in and out of the car twice with a rear seal leak. Finally found the issue and turned out to be the eagle crank was out of round on the seal surface (brand new eagle crank) Spec is .006 and mine was .007. Had it machined and ran on the dyno and problem solved. I know rear seal leak is a common problem with the 440 and aftermarket crank and just thought I would share what we found.
 
Have you run the engine again? .001 out doesn't seem like it would cause a seal problem. I may be wrong though.
 
The faster it would turn it would act as a pump and slosh oil out because it's in the shape of a cam... the real question is how come nobody caught it when they balanced the shaft.....
 
How in the world could the crank seal journal be off center? It's not machined at the same time as the mains? You'd really have to make an effort to screw that up.
Doug
 
Turns out it still leaks. Engine builder had it on and off the dyno 4 times and still leaking. Any ideas? Eagle crank with knurling, has anyone had luck with rope seals?
 
Reminds me of the cooling and sending unit threads. Same problem over and over and over with no fix. My rear main on the 440 does not leak. Why? Got the right seal from the right source installed by the right Mopar guru. Even the guys who sell the fancy fool proof seals don't know how the hell to tell you to install them. Good luck.
 
You say you have the knurl or lines on the seal surface? Are they going the right way for the rotation? If you think of them as a screw thread they should turn in the direction where they push oil back into the engine. Really those lines are for use with a rope seal so if all else fails use one of those. Another thing is that seal cap is supposed to seal to the block and pan as well as the crank. .007" out of round, as crappy as that is for a ground part, shouldn't be too much of an issue for a rubber lip seal.
 
It is not the seal itself, nor the seal surface on the Crank... been there done this a hundred times.

Listen closely.... if you want to cure the rear main leak, once and for all !

The problem;
The groove in the Block, that holds the upper half of the rear seal, were NOT machined at the same time as the Mains on BB Mopars, and are NOT concentric with the mains.
If you look closely with the Crank and upper seal half installed flush with the parting line in the Block, you will see that one side will be compressed with the seal lip "tight" and sealing on the Crank..... and the other(offending) side barely touching.
This is a very common problem on BB Mopars and should be checked/ corrected on assembly.

The cure;
Offset the Seal installation about 1/4" to 3/8" above the parting line on the "offending" non-contacting side.... so that it fits UP into the Seal retainer as it is lowered into place.... then use a small screwdriver to move the retainer OVER as it is installed.... dragging the offending seal side into contact with the Crank.
Obviously here, the retainer side fibre pieces are deleted to allow the retainer side-to-side movement. Clean well with brake clean afterward and just silicon up the retainer from the outside.
Tip;
usually a good idea..... to also have your guy machine about .010" off the retainer on his Connecting Rod Cap Cutter first, before installation. This provides a little added Seal compression against the Crank.

There has been about 40.... Billet, shiney, start trek, 007, wiz-bang type Seal retainers offered in the aftermarket for BB Mopars....NONE cure the PROBLEM.... because the retainer is NOT the PROBLEM !.
It is the groove offset in the Block !
So install the seal offset above the parting line on one side..... (AFTER you first mock-up with it installed flush to determine which side the seal is loose on), then use the Seal Retainer as it is installed, to drag the Seal over into Crank contact.
Bob @ rmp Race Engines
 
Challenger340 said:
It is not the seal itself, nor the seal surface on the Crank... been there done this a hundred times.

Listen closely.... if you want to cure the rear main leak, once and for all !

The problem;
The groove in the Block, that holds the upper half of the rear seal, were NOT machined at the same time as the Mains on BB Mopars, and are NOT concentric with the mains.
If you look closely with the Crank and upper seal half installed flush with the parting line in the Block, you will see that one side will be compressed with the seal lip "tight" and sealing on the Crank..... and the other(offending) side barely touching.
This is a very common problem on BB Mopars and should be checked/ corrected on assembly.

The cure;
Offset the Seal installation about 1/4" to 3/8" above the parting line on the "offending" non-contacting side.... so that it fits UP into the Seal retainer as it is lowered into place.... then use a small screwdriver to move the retainer OVER as it is installed.... dragging the offending seal side into contact with the Crank.
Obviously here, the retainer side fibre pieces are deleted to allow the retainer side-to-side movement. Clean well with brake clean afterward and just silicon up the retainer from the outside.
Tip;
usually a good idea..... to also have your guy machine about .010" off the retainer on his Connecting Rod Cap Cutter first, before installation. This provides a little added Seal compression against the Crank.

There has been about 40.... Billet, shiney, start trek, 007, wiz-bang type Seal retainers offered in the aftermarket for BB Mopars....NONE cure the PROBLEM.... because the retainer is NOT the PROBLEM !.
It is the groove offset in the Block !
So install the seal offset above the parting line on one side..... (AFTER you first mock-up with it installed flush to determine which side the seal is loose on), then use the Seal Retainer as it is installed, to drag the Seal over into Crank contact.
Bob @ rmp Race Engines
Click to expand...

Great information, thanks for taking the time to share your knowledge with us...
 
Put a rope seal in and it stopped the leak. Had a look at the seal groove and yes it was offset. Quite bad actually. Rope seal cured it and I went racing.
 
I have ALWAYS offset my seal's. That way you don't have the same parting line.
 
They can leak from between the seal and the block and cap if it had the slightest amount of oil... laquor thinner and a lint free cloth and some non hardening sealer on the surfaces and a wipe of oil on the sealing surface on the crank let it set up over night.
 
appleby66 said:
Just had a 440ci bracket engine built and had it in and out of the car twice with a rear seal leak. Finally found the issue and turned out to be the eagle crank was out of round on the seal surface (brand new eagle crank) Spec is .006 and mine was .007. Had it machined and ran on the dyno and problem solved. I know rear seal leak is a common problem with the 440 and aftermarket crank and just thought I would share what we found.
Click to expand...
Chryslers way of oiling the pinion in a Dana
 
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