Imo000

If someone would measure the dimensions of the tool, it might be easier for others to have one made, rather than to ship it back and forth.

blown 87

The cons of having it flush or all the way back is that it is going to leak.
No pros that I can think of, cause they are not in the right spot.
The problem with driving it in all the way is that the rear mating parts where the girdle and block come together are not really flat and you can bend that seal oh so easy.

I also do not think that most folks understand how important it is to have the seal square.

When you use a seal to drive one in you can bend the seal and never know it, seen it, done it, more than once.

Fitting a piece of PVC pipe is a far better option than using a old seal if you can not get the right tool.

blown 87

I will try to get some pics and measurements today or tomorrow for you.

Shipping to Canada is a issue, takes forever.

928nut

This is tricky and simple at the same time. I did mine couple of years ago and had similar questions. Ultimately, the seal has to seal properly on both sides. So you have to go deep enough to go past the notch in the block and ensure the inner seal-lip hasn't gone past the edge of the sealing flange on the crank. Of course you know all this, you are an experienced mechanic, from what I can tell.

One thing I want to point out is to carefully compare the old and new seal. The new seal I got wasn't exactly the same as the old one. The old seal was flush and sealed OK. The new seal, when installed flush didn't seal off the notch. If I recall correctly, even the inner sealing lip wasn't spaced exactly as the old one. Attached pic shows how deep I went with that particular seal.

Jan

mark kibort

1mm past flush. Ive done flush for a a few of the engines Ive built and none have leaked. The stroker came with the seal way past flush and it doesnt leak, so I dont know, it probably doesnt matter, so maybe 1mm is a happy medium!

Sueden

For a tool I used a 4 inch plastic screw in sewer plug that I got at home depo for $2.15 and then used a hole saw to cut out for the crank ! Just take your rms with you and line it up at the home depo and you will see . Ite only about 3/4 " thick . sku #39236 30760 6 I think thats the right number.

Imo000

I've noticed it too that the original Porsche seal has the outside of the seal rubber coated from top to bottom. The replacement Victor Reinz is only half covered with ruber. The first half is exposed steel and about half way through the rubber coating starts. Maybe that's why the Victor Reinz seals can leak if they are not pushed in far enough to go pass the notch. probalby makes it a little easier to install.

In the factory originals case, this is probalby not a problem as the entire outter edge is cover in rubber. I'll take some pics when my spare seal (local Napa had one) comes in at 2pm.







Thanks! The only dimension I really need is the height of the lip (the part that pushes the seal past flush). The rest I can be figured out from the dimensions of the seal.

Imo000

Anyone has a picture of the two halves of the block bolted together but without the seal or crank, taken from the rear seal point of view?

My logic tells me that the inner lip of the block (the part that the seal would eventually bottom out to) is is machines our when the two halves are bolted together. The front edge appears to be machines as one, so the back shoud be too....unless for some reason Porsche decided not to.

blown 87

Mine was not flat at the back, could have been a fluke though.

dprantl

I've always installed shaft lip seals flush. I have installed two 928 rear crank seals so far, both of them flush and neither leak. It is sometimes a PITA without the correct tool, but you just have to have patience and strong fingers. The seals have a tendency to leak if they are not properly lubricated before installation, if they are treated too roughly during install, or the spring ring inside the seal becoming dislodged during installation.

Dan
'91 928GT S/C 475hp/460lb.ft

Tom928

I made a tool from ABS plastic pipe and a flat cover with holes for bolts (not the flywheel bolts) as a install device. Put a little petroleum jelly around the inside lip of the seal. Put the new seal in place with the old seal (reversed) behind it. Put the install device in place and put in the bolts. Line everything up and begin tightening the bolts. Install the seal just a little past flush making sure it covers the indent in the block. Maybe 1-2mm.
One thing I did notice was the new seal (Porsche) was just a little shorter than the original.

This is the method I used to install the rear main seal. That was Feb this year and I have no leaks.

Hope this helps.

Bill Ball

I did mine about 85K miles ago. The original seal started leaking right after a long series of dyno runs one day. I installed the new seal w/o removing the TT, so I had very little room to use a proper driver. So, I did it like Imo000. Not kosher, but all I could do with my choice of approaches. I installed the new seal just below flush - well essentially flush. No leaks since. Lucky me again!