With the torque tube and trans out, this would be the ideal time to do the rear main seal. I have read the archives about it and found that in some situations, it leaks after being replaced!

Currently, the seal is NOT leaking; however, it's likely the original which been in there for 115K miles. I feel I should replace it but do not want a new seal that leaks and have to tear things apart to re do it.

Any tips or tricks on getting the old one out and the new one in so it does not leak?

Thanks for any help,

 

Do change it.
I did my TT and did not change it and less than a month later I had to take it all back out to do the seal.

There is a grove for putting a screwdriver in to get the old seal out, be very careful not to damage anything.

Either buy the correct seal driver or make one, do not just use a hammer.

 

Search is your friend. There is a "how to" here complete w/picts.

 

are you supposed to install the seal dry ?

I remember someone replacing the front seal using oil, but then it just popped out when driving.

 

Dry on the outside, slight coating of grease on the inner lips.

 

Blown87

For removal - I have my trusty custom seal removal tool (bent screwdriver). For a driver, I plan on making an install tool from ABS plastic with an end piece and holes for the flywheel bolts. This way I can press it in.

This maybe a stupid question, but how do you keep the flywheel from moving when removing/installing the bolts?
Screwdriver against flywheel teeth seems a bit risky. C-clamp on flywheel against the block?

 

I would leave it alone having had a new one leak. Original blew at the track after ~150k miles. YMMV.

Brace the flywheel by installing a few bolts and running a long enough bar (pole, crowbar, etc.) through them so it's braced against the floor. This will help turning the engine from behind as well.

 

This maybe a stupid question, but what kind of grease? - or does it matter?
I have some stuff I got from the Porsche dealer marked "CV boot grease" - will that work?

 

I was told by a Porsche trained mechanic when the 928 was still in production to use Vasoline. I took his advise and have had no problems for 4 years now.
Be sure to inspect the area/block and crank shaft for ANY burs etc. before installing the new seal.

 

Vaseline - that's interesting!
I have heard that some of the old engine builders using Vaseline for engine assembly.

On other engines (Chevy, Ford, etc); I had always heard to use engine oil on the seal; however, several people on the forum mentioned grease for the 928.
Vaseline does sound like it would keep the seal lubed until oil begins to flow.

I checked the block and crank for bur's, nicks etc - Looks good and clean.

Thanks for the feedback,

 

& recommended to use Vaseline ?

You guys should get back to technical stuff before this thread is closed

Marton

 

I use a synthetic grease, but pretty much any type of grease should work.