Published in the May 2013 issue of “Die Porsche Kassette”
If you haven’t read “The BAD, the UGLY and the GOOD part 1” go back and do it. It’s important to understand the causes that create the failures and therefore how to fix the issues.
If you’ve read it, fret no longer the answer is here ... THE GOOD ! ...
This is an OEM single row bearing which just came off a Carrera 996.
You can see how the bearing is sealed.
There is no way that this bearing would get proper lubrication under the conditions where it is installed.
This bearing was extracted as it had just begun to fail. The owner was very lucky we caught it in time.
OK!, so what’s the BIG SOLUTION?
Actually it is a quite simple concept with a not-so-simple execution.
If the problem is lack of lubrication, then the solution has to be proper lubrication. Duh!
But the location of the bearing and the shape of the flange create difficulties.
The bearing and flange are sandwiched between the engine’s block and the rotating flywheel just a few millimeters away so there is very little room to work in. You can see what we mean below: The top shaft with a sprocket is the starter motor which engages with the outside teeth of the flywheel which in turn is bolted to the crankshaft in the center of the engine. The triangular piece on the bottom of the bell housing is the flange which supports the bearing at the end of the intermediate shaft.
The solution is to install direct oil feed to the IMS bearing using the engine’s own pressurized oil.
The M96/M97 engines have several unused high pressure oil ports already built into the block, so it is very easy to tap into one of them.
A high-pressure stainless-steel-braided oil line is connected to the port which will carries pressurized oil when the engine is running and its oil pumps are operating.
Then, a new flange is installed, replacing the factory flange. This flange, as you can see, is much flatter than the OEM to make room for the integrated oil injection system.
This is where the other end of the high-pressure oil line that comes from the engine connects to.
A small notch needs to be cut into the edge of the bell housing to allow for the routing of the oil hose.
When this new flange is installed, it is recommended that the existing IMS bearing be replaced with either a new ceramic-ball bearing or a new OEM all steel bearing.
When an OEM bearing is installed, the outside seal is removed to allow the oil to completely bathe the rotating balls and inner race of the bearing in clean, filtered, circulating oil, which reduces friction and heat, and thus guarantees a long life for the bearing.
The oil that overflows from the bearing, just makes its way down to the oil pan to be filtered again and pumped through the system once more.
To install the kit, the transmission, the clutch and/or the torque converter and the flywheel need to be removed from the car.
The engine then needs to be locked in TDC and then removal of the flange and/or bearing and installation of the new parts can be done.
It also makes sense to replace the clutch at this point, since there won’t be additional labor in doing so, just the cost of the new clutch parts.
Any Porsche shop will be able to install this kit as well as knowledgeable individuals with the right tools and equipment.
This IMS Bearing Fix was developed in South Florida where it’s been installed and tested on street and race cars.
There is another somewhat similar (in concept) solution developed in Georgia. This other solution includes the replacement of the OEM IMS ball bearing with a plain journal bearing, which also has a direct oil feed system. Unfortunately this solution only applies to the first generation single-row IMS bearing cars from MY 2000 through 2005.
It is important to note that other conditions have also been considered to be additional possible causes of bearing damage in these engines, in particular, vibration.
These M96/M97 engines all develop a 3,000 RPM harmonic vibration intrinsic to the design of the engine.
It has been generally recommended that you do not sustain a 3,000 RPM engine speed for extended periods of time when driving on the highways. It is easy to set the cruise control at 72 MPH which, in high gear is very close to the described 3,000 RPM. Just reduce or increase speed a bit to avoid holding the engine at a steady at 3,000 RPM.
Also, the front engine mount on the Boxster and Cayman is a wear item, generally neglected, that needs to be replaced at 50,000 mile intervals. A good front engine mounts helps to mitigate the 3,000 RPM shudder and transmits much less vibration from the engine.
To learn more about the Final Fix for the IMS bearing and how to order one, please visit my website at: wwwPedrosGarage.com.
Ⓒ2013 Technolab / PedrosGarage.com