intermediate shaft seal and cover

[MNBoxster]

Originally Posted by KronixSpeed

hey question? what is the difference between the old style seal and the new?

"I used the new "Cayenne" style RMS."

i also have this new seal when my rms was fixed last year november. is it really
better is pretty much my question?

Hi,

My understanding is that it's design (profile) and perhaps it's material composition make it more pliable and better able to adapt to a Crankshaft opening in the Block which is not exactly centered on the Crank's spin axis.

But, it still amounts to only a better Band-Aid and I am a little skeptical because I don't think this latest fix has racked up that many miles to be deemed a once-and-for-all fix of the issue. We can only hope...

Happy Motoring!... Jim'99

[rodsnhawgs]

As promised, here's a few pics in successive threads. I'll make a few comments along w/ the pics. Also, refer to the links that are noted/notable resources. There are others on the "net", but these are a couple of really good ones.

First, let me say that even though this could be a "driveway" job, as you'll see from the pics, my shop is well equipped which made it much easier and safer. Second, this job is not beyond the capabilities of any of you with a decent level of mechanical aptitude and most basic hand tools. You may need to buy, borrow, or rent a few tools, but the offset in labor saved would be well worth the investment in my opinion. OK, let's get to it:

The Bentley Svc manual shows an engine support tool to "hang" the engine from while the transmission is removed. This is because the downward forces on the engine/trans are supported by the (transmission) rear mounts. Anyway, I made the same rig out of a 2X4, a piece of allthread , and a short section of chain (see pic). This allows for adjustment up/down and support w/ the trans removed. The other pic shows the car on the rack w/ rear supported on jack stands so the wheels and axles can turn.

[rodsnhawgs]

The next thing I encountered was the torque applied to the rear axle hub retaining nuts. There is no reference to this in the Bentley so let me tell you what it is... 340 foot pounds. I found this out from the tech at the local dealership. BTW, it's not a bad idea to go in and establish a little relationship w/ this guy so you can pick his brain and work station computer if need be...

Anyway, with that spec revealed, I knew what kind of forces I'd need to apply to remove the nuts.

The rest of the removal was very straightforward w/ no surprises. In actuallity, I found the Boxster to be fairly easy to work on. Most items are reasonably accessible, the fasteners are stainless steel, and the specialized tools that the Bentley shows are easily substituted w/ a little thought.

Here's a pic w/ the RMS drip before I started; the exhaust removed; a couple of others w/ the transmission removed. As you can see, this is a tiptronic car.

[rodsnhawgs]

Now we're down to it. With the flexplate (flywheel on standard cars) removed, the offending RMS is exposed. This is the old style seal - if you'll refer to the Renntech link, you can see and read all about these and how the newer Cayenne style seal is the latest replacement. My personal opinion on the seal failures, based on limited knowledge here...:

The material of construction (MOC) appears to have been incorrect for the application. However, this is secondary to the design flaw of the crank support (or lack of) at the rear of the block. I think these two issues are what cause the RMS leak issue. W/ the crank unsupported, the rotating mass and associated harmonics make it impossible to maintain a straight axis through the crank centerline. Lots of heat is generated as the seal "rubs" on the rear crank causing the seal to become less pliable over time. As the seal hardens and the harmonics continue, oil naturally finds a path out. My/our hope, given the fact that Porsche has decided to ignor the unsupported crank issue, is that the new seal MOC will maintain its integrity and thus eliminate/reduce the number of seal failures we're seeing. It's a bandaid fix, but if it works....

OK, on to the show: Here you can see the leaky seal ( 2 pics). With the seal removed, the pics show the wear mark on the crank (please excuse the out of focus pic). In my case, the seal did not wear a groove in the crank, but only left a score mark. My guess is that some failures are a result of an actual groove left in the crank - check this closely. Part of the recommended r & r is that the new seal be set deeper into the block (see thread below). I concur... I also followed the recommendation that the four block bolts and three intermediate shaft bolts be replaced. This is cheap insurance if you're this deep into the project. With the seal replaced, the reassembly is again straightforward. If you go to my first post in this thread (int shaft seal...) you can see the new seal installed in the pic. I replaced all eight flexplate bolts w/ new ones (once again as cheap insurance @ $1 each). Use locktight blue on them as Porsche bolts don't use any type of lockwasher. Please refer to the links below for more details.

[rodsnhawgs]

A few items worth noting. Apparently Porsche uses two different size fasteners on the inboard half-shaft hubs. The dealer tech cautioned me (and I you) to be sure to torque these to the correct specs. On the tiptronic cars, the starter must be removed to access the torque converter bolts - be sure to use a suitable retainer, as shown in the Bentley, on the torque converter so it doesn't fall out when removing the transmission. I also stuffed a rag in the starter/trans opening so I wouldn't drop a torque converter bolt down in the trans bellhousing when going in or out with these bolts. I had all the parts in-hand before I started so as to avoid untimely delays.

One other thing that bears noting. I didn't use the go/no-go tool to measure the opening. I didn't use the Porsche seal installation tool either. Because I've worked on cars most of my life, and have a good selection of tools and measuring devices I was able to do this without these specialized tools. Use your own judgement as to your abilities. Be honest with yourself - you may want to opt for these tools - again, probably a good investment.

So far, so good...as noted below, total parts cost was less than $150 US. If you attempt this yourself, go slow, refer to the good folks here and on other sites often, and be safe.

[NickCats]

rodsnhawgs, thanks so much for sharing this !

How long did this take total ? Did you finish in one day or spend multiple days ?

[rodsnhawgs]

NickCats: Because I was in a learning curve (Boxster is a new animal to me) it took longer than a Porsche tech of course... but even so, I did it over about 3 days and probably 18 hours total. I lost a lot of time w/ the intermediate shaft problem (recall the original post on this thread). I'd say if I had to do it again in the near future (let's hope not!), I could probably do it in 10-12 hours. I'd be interested in knowing what the Porsche flat rate calls for... anyone know?