Intermediate shaft seal leak questions.

[HFR_Racer]

I hope everyone is making good progress the their winter Porsche projects and can provide some good advice for one of mine..

I have an oil leak near my engine pulley / intermediate shaft on my 87 930 with 86k miles. Once I get the cover off that surrounds the pulley I'll be able to tell more but it's wet in there (see attached photo):



The engine case has never been apart but I plan this for the next winter. This winter I'm going through the transmission and cleaning up the engine a bit.


My questions are as follows: I've ordered the o-rings and seal to seal up this area but I'd like more detailed information on how to properly complete this repair. I've done a search and am finding only bits and pieces.

1) Intermediate shaft area:

I assume I can remove the three-(3) bolt cover, peel out the old o-ring and just replace it. Do I need a o-ring lube? If so, any recommendations? or just put it in dry. I've seen that ThreeBond 1211 to seal the cover to the case is recommended. Does the o-ring rest in a groove in the case? Is it hard to remove from the case? Any other obsticles that I should be aware of?

2) Crank pulley o-ring and lip seal:

I see that you can loosen the crank pulley by putting the car in high gear and applying the brakes while you use an impact to remove the bolt. I assume that the bolt is a right-hand thread bolt? Is this correct?

Once I remove the cank bolt I assume that I use a standard gear puller to pull the pulley off of the crank. Does the pulley remove easily? Any chance of bending the pulley lips during removal? Any special removal method?

I assume I can just peel out the old o-ring and oil lip seal replace them? Do I need a o-ring lube? Shall I use a sealant to seal the O.D. surface of the lip seal to the case? ThreeBond 1211 sealant??

Does the o-ring rest in a groove in the case? Is it hard to remove from the case? Do I really need an oil seal install tool? Can't I use a piece of steel rod (large O.D.) as a drift punch to install the lip seal?

Thank you for any and all assistance,
HFR_Racer

[Walt Fricke]

HFR

It is not too likely that your intermediate shaft cover plate is the source of your leak. Older engines used a gasket under a 3 bolt plate, and it was unlikely to leak. Yours uses an O ring with a 2 bolt piece. Should be no problem replacing the ring. You could use some silicone paste on the ring, the idea being that the ring can then move to accomodate thermal movement more easily. Makes it easier to install also, but some oil would do that too. Not a big deal, and I'd check closely to see if it is leaking, as I don't see it as a common source of leakage. Not on the older engines, anyway. No reason to fuss with it if it isn't leaking.

Pulley thread is standard right hand. You say you have the tranny out? So your engine is also, right? Your impact gun should do the trick on the bolt, but it is easy to rig up a way to stop the crank from rotating. Pull the pressure plate, reinstall one of the PP bolts, and use an open end wrench between that and one of the engine to tranny studs (or bolts). I can torque the flywheel to 150 lbs/ft with nothing more than that. Steel in compression is mighty strong.

Or is your tranny work really CV repair or shift linkage, and all is still in the car? You can still change the crank seal, but have to pull stuff like the muffler, some sheet metal, and the rear motor mount with the engine propped up on something substantial, like a stout wood block (don't trust a hydraulic jack to hold height over a long period of time) so you can get at the pulley bolt. Might be harder to get an impact wrench in there, though a cheater bar on your socket should work.

Yes, the pulley bolt is right hand thread. Doesn't need to be otherwise, as the pulley is located (registered) with a pin (that alone isn't enough to deal with missed shift overrevs, hence I think the high torque on this bolt). No pullers should be needed, as it is not any kind of press fit. The little lip on the back side just serves to center it.

The pulley end seal is inserted into the #8 main bearing. This is a large, thick tube of some aluminum-like material, with orfices for getting oil into the crank as well as into its ID. It is this #8 bearing that has an O ring. So you can't get at that ring without splitting the case. Forget about that part of it.

The seal can be pried out once the pulley is off. I don't own the tool, though at times I have wished maybe I did. I do the replacement with the bearing on my bench as part of a rebuild to make this easier. But it can be done easily enough with the engine together. Just be patient. Punches aren't the right thing - the rubbery exterior covering of the seal is easy to damage. As with most seals, the trick is being able to avoid the teeter-totter frustration, where pushing down on one part causes the opposite side to rock up. Patience.

Is this leak worth really worth fussing with? Motor new to you? Clean it up well, see how much accumulates over what useage? You know the adage: if it isn't leaking it is out of oil. Doesn't have to be that way, but periodic cleaning might be easier than replacing something which may or may not be the source.

Our website host has a book on rebuilding 911 engines. A very good value, wonderful pictures, etc. He also wrote 101 Projects for your 911, which is also worth having, though I don't have its table of contents memorized so don't know if it covers this seal replacement. A guy who does his own work on our vintage 911 ought to own both.

Disclaimer - I'm not a turbo guy, so if some turbo plumbing makes doing any of this harder, don't cuss at me. But the seals are identical.

Walt Fricke

[HFR_Racer]

Thank you for your response Walt..

My 930 is an '87 model and I do need to fix the oil leak since it drips directly on the cross-over pipe.

Upon your response, I did review Wayne's engine rebuild book and it shows how the o-ring is on the O.D. of the #8 crank bearing. I won't be ordering this part as you mentioned. It also shows the lip seal that is housed within the #8 bearing and describes how to install it as well using the Curil-T selaant.

However Wayne's engine book shows an early style intermediate shaft cover that uses a gasket. I don't think mine has a gasket per the PET diagrams. It doesn't show it in my Haynes manual either.

Anyone have a photo showing what it looks like under the intermediate shaft cover?