Name that Leak - Please?

[Gelbster]

GBox needs to give you the tech advice on this, not us !
For example, you need to examine the input shaft for wear/marking where the lip of the seal fits.If there is any discernible marking ,discuss with GBox because fitting a new seal may be futile.
If the marking is slight, can it be 'improved' ?
If it can, is it possible to fit the new seal to a slightly different depth ? GBox to advise.
Similar issues arise with the RMS and sometimes experts(not me) suggest setting the new seal to a different depth to avoid repeat leak problems.
Let us know what happens?

[hoyabob2003]

You're right, I'll be in touch with them again. The guy on the phone did not seem concerned at all. He just told me to get a new seal, pick the old seal out with some picks and tap the new one back in. There is a lip where it is supposed to stop and if you tap the new seal past the lip, it falls into the tranny. You're right though - why did it fail in the first place, only 2500 miles since the rebuild? This can't be a very common problem since I have rarely found this issue mentioned in the forums.

[hoyabob2003]

Well, it was definitely the input shaft seal leaking. Gbox was equally puzzled by this but helpful and responsive over the phone.

They requested that I confirm it was for sure not crankcase oil and that my pilot bearing was not seized or missing.

I pulled the clutch and flywheel - both nearly brand new and in good working order. The RMS and IMS were both dry. I did install a new pilot bearing just to eliminate that as a possibility.

I pulled the main shaft seal of the transmission to find that it was definitely leaking. Interestingly, it was not an OEM part. Comparing the 2 seals side by side, the OEM Porsche part was clearly more robust and had more surface sealing area. I would have expected that a high end company like GBox would have used OEM seals, and perhaps seal failure is really the root cause here.

Then again, only time will tell...

Here's a picture of the 2 seals side by side (The non-OEM seal is damaged due to removal)

[Gelbster]

Were you just unlucky and got the wrong sub-spec generic seal ? A one-off problem -lets hope.
Or are all the recent GBox 6 speed transmission rebuilds going to fail because of this seal ?
Can you Post the exact markings from the correct seal so we know what to check for?
If you can also give me the markings from the failed seal ,I can research and try to give a comparison of the two specifications.

[hoyabob2003]

The seal is marked 111801 28 40 8R 8 SOG

It looks exactly like this one:

2004 Porsche Boxster S Convertible - Transmission - Page 2

The OEM Porsche Part that I got from the dealer is:

996 301 805 00

There is quite the difference in cost between these 2 - the OEM is 3x the cost - but the photos don't do it justice as the OEM is clearly just a much more robust part.

[911monty]

Originally Posted by hoyabob2003

There is quite the difference in cost between these 2 - the OEM is 3x the cost - but the photos don't do it justice as the OEM is clearly just a much more robust part.

This is the same thing I found when I changed the output shaft seals on my trans. I ordered the OEM part from Pelican, but when I pulled the existing seal it was clearly a much better part. I then ordered the Porsche seals from Pelican. More money but a much better part.

[Gelbster]

Looks like that us just a generic seal ;
Also fitted to Mitsubishi. I found generics for $3.This one is branded for $9
MITSUBISHI ENGINE OIL SEAL 28*40*8 R mm NJ 373
Here are some SKF with higher temperature material:
https://www.motionindustries.com/productCatalogSearch.jsp?q=28+X+40+X+10++++MM+A-NBR+SEAL
My personal rules with seals and bearings is to buy the best/most expensive:
https://www.motionindustries.com/productDetail.jsp?sku=00611488
Because the R&R costs 100X that of the generic seal price.
ASk California MotorSports,GTGears, or "Erick"to comment.They are much smarter than me on this issue.

[hoyabob2003]

Admittedly, I'm a bit disappointed with GBox for using an inferior part in my rebuild. There's no excuse for having to pull a leaking tranny after 2500 miles.