Balance shaft leaks ... STILL!

krahm · 01-04-2006, 07:15 AM

Okay, I'm back in there for a cylinder head re-build and to correct a few things that I should have gotten fixed when I was in there last year. One is that the balance shaft seal is still leaking. The first time around I replaced the seal, the metal collar that goes on the end of the shaft, the thin plastic shim that goes behind the collar, and the rubber o-ring on the housing. I don't think I missed anything. I see some old posts where people have had the same problem, so they just kept replacing the seal til it worked. Is that the way to go? or is there something I should be checking/doing? I'll try greasing the seal this time (I think I only oiled it last time). Any other suggestions? Thx.

pm9146 · 01-04-2006, 11:26 AM

The upper and lower seals are different, but i doubt you put the wrong seal in the wrong position as they are, I believe, different ODs. They are also designed for different rotation as the balance shafts rotate one clockwise and the other counter clockwise and have little arows on them designating which is which. I believe the difference in diameter is so you can't confuse them. Can you tell where it's leading? Between the seal race and the inside of the seal or is it between the outside of the seal and the housing?

hpaulb · 01-04-2006, 11:35 AM

Can't express a most important item? I think? When I did mine, there was only vaige references to that micro thin clear plastic shim. It was only after I saw the blow-up diagram that I actuauly had some inclination there was somthing else there. Never saw it when I took it apart. Found one still on the shaft and the other on the table. Didn't even know what it looked like so was fishing in the dark. Somone finaly explained it to me although I never found out what it does. Quessed it must spin off oil so it doesn't leak through the seal? Just know that Porsche is so tight a$$ spec'ed that it must do somthing.

tab tanner · 01-04-2006, 05:50 PM

It seals the shaft to the seal bushing, without it it will LEAK

mike944 · 01-04-2006, 07:27 PM

has anyone else tried O-rings inside those spacer bushings? There's a groove in the ID that perfectly fits an O-ring (can't remember the size number) I used an O-ring, in addition to the clear plastic spacers. Never had a leak

Slam · 01-05-2006, 11:51 AM

Yes, I tried to O-ring the thing. Didn't leak for a while, but soon enough the seal was destroyed due to lack of lubrication.

krahm · 01-06-2006, 06:31 AM

I triple-checked the part #s on the seals, so I'm relatively certain I got them where they're supposed to go. I also replaced the plastic shim the first time around. It looks like it's leaking between the bushing and the seal, but just to be sure, I'll replace the plastic shim again this time.

pm9146 · 01-06-2006, 07:23 AM

You might check the bushing carefully when you have it apart this time to make sure you don't have a very slight groove where the seal lip contacts it and also make sure the spring under the seal lip didn't become displaced on installation. If there is a slight groove in the bushing you should replace it.
Pat