Leaking Crankshaft / Flywheel Oil Seal

[vwlover77]

I installed a new transmission input shaft seal on my 78 Westy in the early Spring of 2010, with good results - until now. I found a spot of gear oil 3 inches in diameter on the garage floor this morning. (Drove the Bus about 150 miles yesterday, mostly highway.) It's dripping from the hole at the bottom of the engine / transmission mating surface, so I'm sure it's the input shaft seal. This seal has around 4000 miles maximum on it.

Did I just get a bad seal, or could something else be going on to cause it to start leaking so soon?

[hambone]

Hmm, there could be a slight imperfection where the shaft meets the seal. That's a long/short time to fail.

[Amskeptic]

Oh man, who can tell? Some parts have been sitting on the shelf for since forever, others are garbage, and your input shaft could be wobbling or skating around in the transmission because it is not fully hooked up in the pilot bearing.
Sorry about that transmission oil leak.
ColinInCanton

[vwlover77]

Well, guess what? Upon engine removal and inspection, it appears that it's engine oil leaking from the nearly new flywheel/crank seal! Turns out I was supplied a Chinese NTK seal and although there is no visible damage, it's leaking like a sieve.

There is obviously oil radiating out from the center of the flat front side of the flywheel.

New Sabo OE VW seal on order from GoWesty

http://www.gowesty.com/library_article.php?id=535

But the inside of the transmission bellhousing is covered in oil too so I'm replacing the trans input shaft seal again (and will carefully inspect the shaft for any rough spots).

[vdubyah73]

I know you've already solved this question but an often overlooked cause of tranny oil leaks is a plugged vent hole on the nose cone. 150 miles of highway and your gear oil is gonna get warm. when things get warm they expand. when there is no vent the pressure has to go somewhere, so it pushes oil out of any number of locations. this applies to most any gearbox.

[Amskeptic]

Well, guess what? it's engine oil

Oh my. We shall endeavor to be ever more vigilant to the quality of parts we install in our precious chariots.
Yes, we shall.
Glad it wasn't a gallery plug.
Colin

[vwlover77]

I shall double-check the transmission vent hole, but I believe it to be clear since the transmission was rebuilt 4 years ago.

Luckily, despite the GEX origins of my engine, it has threaded oil gallery plugs that have been sealed over with JB Weld by me to prevent any seepage.

Tonight, I rigged up a flexible coupling with some heater hose between my cordless drill and the trans input shaft so I could spin it while holding fine emery cloth to the sealing area. That worked great!

Meanwhile, the flywheel is chucked up to my drill press so I can spin it to smooth out the seal riding area with emery cloth. That also is working out very nicely.

[Amskeptic]

I shall double-check the transmission vent hole, but I believe it to be clear since the transmission was rebuilt 4 years ago.

Luckily, despite the GEX origins of my engine, it has threaded oil gallery plugs that have been sealed over with JB Weld by me to prevent any seepage.

Tonight, I rigged up a flexible coupling with some heater hose between my cordless drill and the trans input shaft so I could spin it while holding fine emery cloth to the sealing area. That worked great!

Meanwhile, the flywheel is chucked up to my drill press so I can spin it to smooth out the seal riding area with emery cloth. That also is working out very nicely.

You will want some tooth at the seal contact area. It would be a nice touch to sand flywheel surface with a diagonal scratch in this direction, sort of like how VW grooves the Type 1 crankshaft at the slinger

front of car . . . . . . . . ^
p plate . . .................................
ring gear IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
seal surface . . . . //////////// .

[BellePlaine]

Does anyone have a photo (or a description of its location) of this transmission vent hole? I didn't realize that it existed.

vwlover77, can you describe further your failed flywheel crank seal? Was it 10 or 12 mms? Color? Where did you order it? I've got different three seals at home that I ordered from three different vendors. Bus Depot's was the orange Victor Reinz - 12 mm thick, German Supply sent me a brown Victor Reinz - 10 mm thick in their flywheel reseal kit (they advertised Vitron), and GoWesty sent me the black Sabo - 12 mm thick seal.

Now, I've read someone (on TS vanagon forum) that 12 mms are for vanagons and 10 mms are for baywindows! Can someone please spell it out for me?!

What does VW say about the lifespan/maintenance of these seals?

[vwlover77]

I'll try to get a picture later, but the transmission vent hole is a very small horizontal hole in the case near the top just behind the shifter connection.

As far as the oil seal, I got the impression from the Go-Westy web site that the part numbers are the same regardless of Vanagon or Bus. Bus Depot also lists the same seal part number for 1972-1991 Bus and Vanagon.

I got the failed seal at the local foreign car parts store. It was black and had NTK molded into it. A web search turned up that NTK is a Chinese supplier.

The best discussion I've found of the various seals is the link in my post above to the Go Westy article. The black Sabo is supposedly the best.

[vwlover77]

You will want some tooth at the seal contact area. It would be a nice touch to sand flywheel surface with a diagonal scratch in this direction, sort of like how VW grooves the Type 1 crankshaft at the slinger

It appears from the photo of the Sabo seal that the seal itself has diagonal grooves molded in to produce pumping action to keep oil from escaping. In that case, I'm thinking I want a smooooooth surface to keep from wearing the sealing lip in any way.....

I should have the Sabo seal in-hand shortly and will post some photos.

[BellePlaine]

I'll try to get a picture later, but the transmission vent hole is a very small horizontal hole in the case near the top just behind the shifter connection.

Thanks. It's now on my to-do list.

As far as the oil seal, I got the impression from the Go-Westy web site that the part numbers are the same regardless of Vanagon or Bus. Bus Depot also lists the same seal part number for 1972-1991 Bus and Vanagon.

I know, I get the same impression. What's weird though is that two out of three vendors gave me a 12 mm (depth) seal and the other sent me a 10 mm seal. Certainly the proper depth of the seal is either one or the other, not both. Odds are that the 12's are the correct but I don't want discount the 10 until I have more proof. Are there differences between aircooled and watercooled? It might not be that far fetched. One could be for aircooled and the other for watercooled. Or have the vendors made a mistake?

I got the failed seal at the local foreign car parts store. It was black and had NTK molded into it. A web search turned up that NTK is a Chinese supplier.

Do you know if it was 10 or 12 mm's thick?

The best discussion I've found of the various seals is the link in my post above to the Go Westy article. The black Sabo is supposedly the best.

That write-up from GoWesty is awesome and the Sabo looks the best of the group that I have, but the article doesn't say if 10's fail more often then 12's. That's what I want to find out.

[Amskeptic]

I'm thinking I want a smooooooth surface to keep from wearing the sealing lip in any way.....

I'm thinking no you don't. Got that? I am thinkin you is wanting some OIL RETENTION big guy, oil RETENTION, HAH? OIL RETENTION in the metal of the flywheel. That seal/flywheel interface gets damn good and hot, and too smooth will prevent the oil you need to keep the stunning shear heat down to a minimum. You know that the wear groove is as shiny and smooth as can be but HEY, look at THAT, the rubber has worn through STEEL! This ain't no wiper blade on glass moment, capiche?
Colin

[BellePlaine]

I'm thinking I want a smooooooth surface to keep from wearing the sealing lip in any way.....

I'm thinking no you don't. Got that? I am thinkin you is wanting some OIL RETENTION big guy, oil RETENTION, HAH? OIL RETENTION in the metal of the flywheel. That seal/flywheel interface gets damn good and hot, and too smooth will prevent the oil you need to keep the stunning shear heat down to a minimum. You know that the wear groove is as shiny and smooth as can be but HEY, look at THAT, the rubber has worn through STEEL! This ain't no wiper blade on glass moment, capiche?
Colin

Promise us that you'll put this little gem in the book.

[Amskeptic]

I'm thinking I want a smooooooth surface to keep from wearing the sealing lip in any way.....

I'm thinking no you don't. Got that? I am thinkin you is wanting some OIL RETENTION big guy, oil RETENTION, HAH? OIL RETENTION in the metal of the flywheel. That seal/flywheel interface gets damn good and hot, and too smooth will prevent the oil you need to keep the stunning shear heat down to a minimum. You know that the wear groove is as shiny and smooth as can be but HEY, look at THAT, the rubber has worn through STEEL! This ain't no wiper blade on glass moment, capiche?
Colin

Promise us that you'll put this little gem in the book.

Will I have any friends left to buy it?