Leaky Flywheel Seal: Symptom of a Bent Crank?

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vwlover77
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Location: North Canton, Ohio
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Leaky Flywheel Seal: Symptom of a Bent Crank?

Post by vwlover77 » Thu Sep 07, 2017 7:40 am

Long story short...... I've replaced the crankshaft seal twice since I rebuilt the engine in my 78 2.0L about 40,000 miles ago. (And it got a new one at the time of the rebuild). They all have leaked oil, enough to reach the clutch lining and produce chatter. The last seal I installed a few years ago was one of the supposedly super-duper ones from Go-Westy. I carefully polished the seal riding surface on the flywheel, and installed the seal so it was protruding from the case to avoid lip contact on the wear area of the flywheel.

I'm wondering if they leak because the crankshaft is bent, and therefore constantly "working" the seal lip back and forth radially as it spins??

Does this make any sense? :scratch:
Don

---------------------------
78 Westy
71 Super Beetle Convertible Autostick

"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen

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Amskeptic
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Re: Leaky Flywheel Seal: Symptom of a Bent Crank?

Post by Amskeptic » Thu Sep 07, 2017 9:42 am

vwlover77 wrote:
Thu Sep 07, 2017 7:40 am
Long story short...... I've replaced the crankshaft seal twice since I rebuilt the engine in my 78 2.0L about 40,000 miles ago. (And it got a new one at the time of the rebuild). They all have leaked oil, enough to reach the clutch lining and produce chatter. The last seal I installed a few years ago was one of the supposedly super-duper ones from Go-Westy. I carefully polished the seal riding surface on the flywheel, and installed the seal so it was protruding from the case to avoid lip contact on the wear area of the flywheel.

I'm wondering if they leak because the crankshaft is bent, and therefore constantly "working" the seal lip back and forth radially as it spins??

Does this make any sense? :scratch:

That is a fanciful diagnosis that I myself have entertained with Chloe. But not likely. Your forged Type 4 crankshaft is not likely to be bent radially through the flywheel area without other symptoms like vibration and nasty bearing wear. However, what is your endplay? Do you get leaks only after highway driving? That would be a gallery plug behind the flywheel that only leaks when the engine is good and warm at operating pressure/temperature. And finally, how bout that graphite o-ring? The merest nick on the end of the crankshaft where the flywheel bolts up can allow oil to escape.
Colin
BobD - 1978 Bus . . . . . . . . . . . 112,660 miles
Chloe - 1970 bus . . . . . . . . . . . 206,845 miles
Naranja - 1977 Westfalia . . . . . 112,885 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,899 miles

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vwlover77
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Re: Leaky Flywheel Seal: Symptom of a Bent Crank?

Post by vwlover77 » Fri Sep 15, 2017 12:58 pm

Hmmmm..... I have not had the strainer plate off in the last few oil changes to look for evidence of nasty bearing wear. I'm planning an oil change this weekend and will do it right this time. Vibration....... Well, that's relative, right? How much it too much?

The gallery plugs all have threaded bolts installed (not by me), and I cleaned and filled them with JB Weld last time I had the engine out. So I hope that would not be the leak source. Could it be the camshaft plug?

Yes, I suppose the graphite o-ring / crankshaft end could also be the culprit. But I'm not in the mood to pull the engine anytime soon to find out! Someday the clutch chatter will finally get the best of me and that will be the time......
Don

---------------------------
78 Westy
71 Super Beetle Convertible Autostick

"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen

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Amskeptic
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Re: Leaky Flywheel Seal: Symptom of a Bent Crank?

Post by Amskeptic » Sat Sep 16, 2017 7:11 pm

vwlover77 wrote:
Fri Sep 15, 2017 12:58 pm
Hmmmm..... I have not had the strainer plate off in the last few oil changes to look for evidence of nasty bearing wear. I'm planning an oil change this weekend and will do it right this time. Vibration....... Well, that's relative, right? How much it too much?

The gallery plugs all have threaded bolts installed (not by me), and I cleaned and filled them with JB Weld last time I had the engine out. So I hope that would not be the leak source. Could it be the camshaft plug?

Yes, I suppose the graphite o-ring / crankshaft end could also be the culprit. But I'm not in the mood to pull the engine anytime soon to find out! Someday the clutch chatter will finally get the best of me and that will be the time......

Time it for my inestimable presence.
Colin
BobD - 1978 Bus . . . . . . . . . . . 112,660 miles
Chloe - 1970 bus . . . . . . . . . . . 206,845 miles
Naranja - 1977 Westfalia . . . . . 112,885 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,899 miles

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