early 915 input shaft seal orientation

[tref]

Hi All,

I'm confused with this diagram in the Porsche manual:
The seal seems to be in the wrong orientation, I expect the writing on the seal to be on the clutch side and the sealing spring ring on the differential side. Is the Porsche manual wrong?

Thanks,
Francois

[tonythetarga]

The seal is meant to go in from the inside, so the manual is correct.

[tref]

Hi Tony,

Yes I'm very aware that the seal goes in from the inside, this does not change my question. Usually the spring ring is on the oil side, in the diagram it is pointing on the dry side.

I think I might have a clue, I took pictures of the seals I have, left one (brown) is the one I removed, middle one (black) is the new replacement, right one is the late version that came with the seal kit.



You can see an arrow on the right side of each seal, the late one is pointing the other direction. Now with an angle:



The mating surface has a slash pattern on the early seal but the late one doesn't have it on the same side:



The slashes are hard to see but they are there.

Conclusion: the manual is right and it's the first time I see a seal that is built backward.

F.

[tsandfor]

Guys, thanks very much for clearing the seal orientation question up, I had the same question.

I had to do my 72 seal about 10 years ago due to leaking gear fluid. Was not as bad as feared to take it apart again.

Last week, while installing a new clutch and flywheel, I notice leakage again. Saw that the helper spring on the seal had fallen off.

Can't imagine how this could happen so this time, I packed the new seal with good quality RTV silicone to keep the spring in place without adversely affecting the function.

Thought about installing the seal with the spring towards the ring gear but will go ahead and put it in per the manual.

Tim

[john walker's workshop]

One seal out there has a larger ID, which would be an instant leaker, so be careful. Fit it on the mainshaft before installing in the case. Don't ask me how I know.

[47silver]

the diagram is correct.
i too thought it was incorrect and installed it the other way
drove a few miles and the transmission lube was flowing out the bottom.
Luckily i found it immediately and it did not ruin my new clutch.
had to remove everything and put it in the correct way and it does not leak.
idiotic design that you cannot replace it with out taking the entire transmission apart.