Question about engine rear seal

NCmau

Member
Shortly I will be reinstalling the crankshaft. I have the one-piece seal for the front, which I believe would be a better approach, at least I have not read any down sides. As far as the rear seal, I will be using the rope style that came with the gasket set. I understand that the rope has to be soaking in oil for couple of hours at least.
My question is, when the rope is pressed into the retainer, do you cut it exactly flush with the block or is there a better method not mentioned in the IT manual?
The old gasket I removed was actually slightly below the surface and the engine had an apparent history of front leakage. I don’t know if it got installed incorrectly or just shrunk. It is hard to believe that if installed correctly, it would shrink.
Anyway, unless I hear a better suggestion, I will use a razor blade and cut it as flush as I can.
 
You have to cut it off "flush" and trim any thread bits because anything sticking out may get mashed between the cap and the block and "shim" the cap away from the block, IMHO.
 

I will make a guess the next question "do I overlap the pan gasket over the rear seal are cut to fit"

I don't soak'em install dry then coat the rope were it rides on the crank shaft with oil are assy lube keeping the ends DRY... THEN apply RTV to the seals were they mate to the oil pan gasket...

I would make a test run on assembling the oil pan so when it came time to seal it i had my ducks in a row... You are using a one piece front seal all you ducks need to be in a row when you go to nail the pan on MAKE A TEST RUN if all is good apply the sealer and nail the pan in place..

If you want a leaker cut the gasket and pre soak the seals in oil...

The other question cut as flush as you can with a new razor blade... Its almost impossible to cut them precision flush but do the best you can...

Were the rear seal retainer fits in the block apply some non Harding sealer to it like peratex aviation form a gasket/sealer... You will need it to seal the head bolts and head gasket if you use a all meal head gasket.


https://www.permatex.com/products/g...x-aviation-form-a-gasket-no-3-sealant-liquid/
 

Good suggestion. Probably would be a good idea to apply the Permatex to all the engine gaskets...you think?
 

No sealer needed on the oil pan gasket rails other than were the timing cover seam meets the oil pan gasket... Your call on the timing cover gasket I seal'em with a very light coat of RTV... What head gasket are you using...
 
(quoted from post at 01:56:46 06/15/18)
No sealer needed on the oil pan gasket rails other than were the timing cover seam meets the oil pan gasket... Your call on the timing cover gasket I seal'em with a very light coat of RTV... What head gasket are you using...

It will be metal.
 
NCMau,

Insert the seal into the groove with your fingers then
Using a rounded tool like a kingpin, ROLL the seal into the groove. When rolling the seal start at one end and roll it to the center of the groove. Then start at the other end, again roll toward the center.

the ropeit flattens out quite a bit when the high cap torque flattens it to conform to the curve of the crankshaft flange). . . But, if it isn't thoroughly ROLLED deep into the groove then the cap torque may sink it very slightly deeper into the groove, decreasing the pressure where 4 wick/rope ends meet at the cap to block face, thus resulting in leakage at those point.

Not having a seal thoroughly pressure rolled (imagine how much pressure torquing the cap will place on it) into the groove
AND an imperfect cutting of the ends are the two main reasons for leakage at the joints.

Best ways for trimming the seal ends . .
A block of wood the same diameter as the crankshaft flange
to hold the seal firmly in place while the ends are cut -- cutting towards the wood of course with a brand new thin blade.
An ideal obviously would be having another old crankshaft so you could rest the crankshaft flange in the cap for cutting.

What I did on my Chev 235, was leave the wick/rope seal 1/32" proud just of the cap side, then I kind of pinched it into a dull pyramid cause I wanted to make sure none of it got between where the cap meets the block. I put a dot of Permatex #2 on the block side rope ends.

Like someone said, be careful to keep the razor knife perfectly parallel to the block and cap faces when cutting; i.e., use two hands with finger pressure on the blade itself to keep it flat.

Terry
 

Replacement N seals are a different animal yes try and roll it in... The replacement seals for a N are ungodly HARD why I dunno I doubt you will make much difference but worth a try...

Its not a graphite impregnated rope seal it shroud be but the replacements are not...
 

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