G50 output shaft seal

Hendog · Hendog's Garage

I'm updating my suspension and am currently working on the front of the car. I'm looking at the back of the car and planning on what I'll be doing there. So far the plan is to replace rear spring plate bushings and torsion bars (ER), shocks (Bilstein Sports), replacing CV boots and repacking CVs.

The CVs are dirty and oily, so my thought is the output shaft seal needs to be replaced. While I have the CVs out, I might as well replace these seals. I serched but came up empty on this procedure (G50). Also looking for the install tool from our host but nothing there as well.

Has anyone done this and can provide some insight?

Jon B · 06-20-2011, 01:53 PM

Porsche tool 9252, available through the Porsche parts system at US $131 MSRP. You can make or find something to do the job well enough, unless you plan on doing alot of these. Measure the installed depth of your current seals before removing them.

KTL · 06-20-2011, 02:07 PM

You can do the install with a piece of PVC pipe that is squarely cut. I made a press tool out of a piece of threaded rod, some washers and a flat cap on the end of the PVC pipe.

The axle flange is removed from the trans by inserting two CV screws diagonally across from each other. Don't put them directly across from each other, where you'd block the bolt holding the flange into the trans. You'll insert a suitable rod between the CV screws to counterhold the flange while you loosen the center bolt. The center bolt is not all that tight, so you don't have to worry about needing a big counterhold force.

Pry the seal out cleanly with a seal removal tool available at any local auto parts store. Make sure you lightly lube the outer rim of the new seal area with some light soapy water or similar, so as to avoid tearing the seal's rubber covering when you press the seal in. Don't use something super slick like oil, which can allow the seal to work it's way back out over time. Axle seals usually don't have this problem like the crankshaft seals do.

When you drive in the new seal, be careful to start it squared-up to the bore and stop when it gets flush with the case. It's possible to drive it in too far and cockeyed, so be patient and seat it carefully.

dtxscott · 06-20-2011, 04:24 PM

Be very careful to not drive it in too far as there is no stop for the seal. It will fall into the diff housing.

KTL · 06-21-2011, 05:43 AM

The side seals/output flanges are backed-up by the diff carrier bearings. So theses seals will not push into the diff housing.

However the input shaft seal (long shaft sticking out of the bellhousing) will indeed push into the diff housing. It'll just hang there on the input shaft. Been there, done that.....