Front Main Seal Installation (DIY?)

[bigjae46]

I’m about to remove my timing cover for a separate repair and replace the front main seal too. Would you recommend this method? Any advice?

There aren’t any video DIYs for this, but I did find a video of someone installing the cover with the seal already in place. They basically just mounted and tightened the bolts, it can’t possibly be that simple though. It’s around 4:40.

https://youtu.be/FTgMMSVow84?si=8-ZSOerMBfhUMV68

I think what makes the front seal tricky is doing the job without removing the cover. So if you’re removing the cover I think it is straight forward.

[///M3RIC]

Apparently I did! It was 2018…If I recall there was a white plastic piece. I would have probably left it in place right until I put the timing cover back on. I’m thinking that white piece keeps the edge of the PTFE seal from rolling or getting caught when sliding it over the crank snout?

I could see how doing the seal with the timing cover on would force you to remove the white plastic piece and the edge of the seal straightens up. So you need a tool to push the seal edge in.

I’m about to remove my timing cover for a separate repair and replace the front main seal too. Would you recommend this method? Any advice?

There aren’t any video DIYs for this, but I did find a video of someone installing the cover with the seal already in place. They basically just mounted and tightened the bolts, it can’t possibly be that simple though. It’s around 4:40.

https://youtu.be/FTgMMSVow84?si=8-ZSOerMBfhUMV68

[cobra]

So it would seem the "groove" in the crank hub is a real thing yes?
I find it hard to imagine that the FMS is doing anything but visually marring the surface but from what I have read it sometimes will not seal when the new FMS is in the same spot as the old seal.

FWIW is oiled my S85 FMS and used Cobra's tool for installation, sealing so far after about 1k miles.

It puts a real measurable groove into the crank hub spacer thing.
I've also seen this on wheel spacers on motorcycles, as well as countershaft sprocket spacers on motorcycles. It's crazy what damage the rubber can do!

Here's a document on PTFE engine seals.

https://www.elring.com/CELUM/10008/10019/TSI09-2011_englisch.pdf

[Cubieman]

So it would seem the "groove" in the crank hub is a real thing yes?
I find it hard to imagine that the FMS is doing anything but visually marring the surface but from what I have read it sometimes will not seal when the new FMS is in the same spot as the old seal.

FWIW is oiled my S85 FMS and used Cobra's tool for installation, sealing so far after about 1k miles.

[bigjae46]

Man, you got lucky. I'm jealous.

Apparently I did! It was 2018…If I recall there was a white plastic piece. I would have probably left it in place right until I put the timing cover back on. I’m thinking that white piece keeps the edge of the PTFE seal from rolling or getting caught when sliding it over the crank snout?

I could see how doing the seal with the timing cover on would force you to remove the white plastic piece and the edge of the seal straightens up. So you need a tool to push the seal edge in.

[heinzboehmer]

I did. I can't remember using a DIY and not sure one existed back then. Didn't think it would be too different from the rear main seal.

Man, you got lucky. I'm jealous.

[bigjae46]

So you installed the seal into the cover and then seal + cover onto the block?

I'm surprised you didn't catch an edge on the crank. The special tool has a taper to slightly stretch the PTFE part of the seal over the crank.

I did. I can't remember using a DIY and not sure one existed back then. Didn't think it would be too different from the rear main seal.

[heinzboehmer]

I did my seal by taking the cover off.

So you installed the seal into the cover and then seal + cover onto the block?

I'm surprised you didn't catch an edge on the crank. The special tool has a taper to slightly stretch the PTFE part of the seal over the crank.

[bigjae46]

I did my seal by taking the cover off. Not leaking yet - 4k track miles? I think it might be worth the extra pain and risk with a fully dressed street car? I'd guess the difficulty is achieving a precise seal placement or at least it makes it harder doing it in car.

Kind of like doing valve cover gaskets on my E90 M3. Don't have to but lowering the front subframe adds some time and makes the job sooooo much easier.

My track car, I can take off the front end in less than 30 minutes which should make the job much easier.

[heinzboehmer]

This was the hardest part of my engine rebuild. I went through 4 seals before I called it quits. Found a guy who's a mechanic at my local Porsche dealership and he came out with special tools to install it (took him 2 tries himself!!) Best of luck.

Yeah this seal sucks. I just did mine and it took me 5 tries and a couple modifications to the special tool.

[Kdubski]

This was the hardest part of my engine rebuild. I went through 4 seals before I called it quits. Found a guy who's a mechanic at my local Porsche dealership and he came out with special tools to install it (took him 2 tries himself!!) Best of luck.

[bigjae46]

I always just replace the OFH gasket whenever I see an oil leak. Then I start looking for the source of the oil leak. Other wise it is too confusing and I always second guess myself.

Seems like front main seals are becoming a more common problem.

[heinzboehmer]

There was a small spray pattern on the driver's side frame rail and below the A/C compressor. On a friends car, the spray pattern was all across the under tray. I'm pretty sure it is the FMS, but it would suck if it is something easier like the OFH gasket.

Mine only did the under tray thing at the very end. Seal was really leaking at that point.

My engine was WAY more grimey than yours. I bet you just caught yours sooner.

[Slideways]

If the FMS was leaking wouldn't it fling oil out wards?

There was a small spray pattern on the driver's side frame rail and below the A/C compressor. On a friends car, the spray pattern was all across the under tray. I'm pretty sure it is the FMS, but it would suck if it is something easier like the OFH gasket.

[cobra]

If the FMS was leaking wouldn't it fling oil out wards?