Question: Front Main Seal Installation
 

Should the new front main seal (pulley side crank seal) lubed with a light coat of oil when install to the case? I've searched and found there are many different opinion about this. Some suggest install it dry, some said lubed the inside lip only (where the surface making contact with the crank shaft), and other said lubed both inside lip and around the seal when drive the seal in. What's your though and experience on this?

I installed the new seal in few weeks ago and still got leak (I lubed both side when install). I found the leak is from where the surface making contact with the crank shaft, because I saw a drop of oil on the tip of shaft after remove the pulley (FYI no leak from #8 bearing o-ring). Genuine Porsche part #999-113-290-41 used. Could the seal defect?

I'm going to re-do. Any suggestion or experience on different brand (Porsche vs. Elring Klinger....etc) Thanks.

FYI, it's a 964 3.6, but I guess it's the same seal up to 996.

There is no oil pressure on the seal, it should seal, what did the crank surface look like? how did #8 bearing fit on the crank, I always us a bit of oil and never had a problem and had good luck with Elring:

Well, you'd always want to lubricate the inside lips, as they are the wear parts so they need lubrication (of course, they are going to get it pretty soon anyway).

As long as you can get it in, I think not lubricating the outside (i.e., install dry) has lots to commend it. Me, when I have the engine apart, I install the seal into the #8 before putting the crank into the case, because it is easier to do this on the bench. Or I just leave the old seal in, if it was working well. The rubber ribs of the seal ought to do the job while holding onto the bearing.

But others like some lube of one sort or another for this.

If the leak is between the seal and the crank snout, then either the seal is bad, or the crank is not smooth.

One trick you can try is to remove the seal (or take a new seal) and shorten the garter spring which hold the seal lips to the crank. Don't have to take off much to add a bit more tension. I forget just how you do this, but it was obvious and not at all difficult.

If you look at a seal spring carefully...you will see the two ends of the spring are sort of "screwed" together.
If you unscrew the ends...and cut off one or two turns...then screw it back...the tension will be greater on the shaft.
Don't take off more than a turn or 2 or you will not be able to get the spring back into the seal.
Bob

Thanks for all the advise. I think I will try the "spring trick" this time.

Yep it works and thats an old engineers trick and I'am a fairly old engineer:D:D:D,it works not contest but it will hasten wear on the seal lip until it becomes flat and then you have a leak.
In my job we do this to get the most of a less than ideal running surface,the long term remedy is machining to undersize and fitting the appropriate size replacement seal or fitting a paperthin stainless steel sleave called a Speedy-sleeve.
In this case I think there may be crank nose wear on the running surface as mentioned.