302 REAR OIL SEAL LEAKING, STILL

[TOM B]

I need mental help now, this is the 3rd time this season I replace the rear oil seal and im loosing it
This is a 2 piece seal with a new crank, bearings and everything else. I installed it correctly and sealed the ends and block to cap surfaces and it still leaks 3 fricken times now I am running a blower but its in a vacuum at about 10 to 12 lbs all the time unless I punch it. No blowby, (new rings) no other oil leaks exept this darn rear main.
I dont get it!! please shoot me, or at least help me

P.S. missed 3 shows now this season









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[fvike]

How is your crankcase ventilation ? If it's not vented properly, it can build up pressure and blow gaskets or seals.

 

[65FBE2]

I have the same problem and its killing me! I will be watching to see if anyone can come up with an answer. Like you I have changed the seal for the third time. This time I even pulled the trans to make sure that it's not coming out the flywheel bolts. I sealed them with lock tight on the threads and a little silicon on the head. I was also told by a very well respected race engine builder that in extreme case's the grove can be out of round in the block so to correct for this place a .01 shim under the seal. So I did that. Still have a rear main leak!

 

[SoCalCruising]

If it's a new crank, why the 2-piece seal? I use a 1-piece on a Scat stroker crank, sealed with The Right Stuff. No problems, so far. If you must use the 2-piece, did you offset (rotate) the seal joints to NOT coincide with where the bearing half-shells come together?

 

[66Runt]

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[TOM B]

WELL I took it out again followed all your steps and hints.
the seal still looked new, it should be, less thst 30 miles on it.
I did notice that the oil pan and engine sit at a tilt towards the rear of car, I think all mustang engines do this but anyhow could all the oil be at the rear seal and when full, flow over to the deep front of pan or maybe to much oil at the rear bearing causing the rear oil leak,, Hmmm, you know that might be it, when I built the engine I opened up some of the top main bearing holes, they were half blocked off when the bearing was put in, so maybe to much oil at the rear bearing and spashing directly at the seal. I know its a long shot but what do you guys think!

 

[66Runt]

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