Pedros Techno DOF IMS fix?

[Jake Raby]

All,
Charles and I are both tied up today, and all weekend with Porsche DFI engine developments.

Our responses will be posted on Monday.

[thom4782]

The available data strongly suggests there is not a lubrication problem AFTER one removes the IMSB seals. Unsealed bearings hardly ever fail. So it looks like we are having a grand "belt and suspenders" debate over reducing the risk of something that isn't a risk in the first place. My 2 cents for the day.

[Jamesp]

I've been out reading the technical literature on various bearing manufacturer websites concerning lubrication. The takeaway is more is not necessarily better, particularly at high speeds, and required viscosity goes down with speed. Spinning the IMS slowly after oil has replaced the grease might not be best approach for IMSB life. Looking at the lubrication requirements makes it clear that a correct application of lubrication is important. Simply squirting oil at the bearing does not appear to be a technically sound solution.

[moresquirt]

With my 60,000 mile 06 Boxster S currently with no problems i am kind off waiting for either the clutch or flywheel to give me issues and then address the IMS issue with one off the remedies mentioned,at the very least pull the seal and let engine oil lube the bearing.(definately not pulling motor and splitting cases) alough the "Solution" would be my ONLY option if i could afford it. Anyone know how long clutches or flywheels usually last,i dont track the car.
Ps: surprised to read that the DOF is already being tweeked .A year from now we will all be much better informed as to the BEST fix for this IMSB issue and the company with the most affordable,reliable and proven method will surely prosper.Good luck to all and we the consumer will be the winner!

[Kirk]

Some food for thought, I'm not sure I would worry about the size/strength of the bearing in MY 06-08 cars. The 6305 bearing in those cars is a monster compared to the single row 6204 in MY 01-05 cars. Here are some comparative pictures I just took. In these pictures the 6305 is just a standard SKF steel bearing. The 6204 is a ceramic hybrid bearing but it's the same size as the OEM steel 6204 bearing.




The 6204 is actually smaller overall than the inside of the outer race of the 6305!



Kirk Bristol

[moresquirt]

Thx for the pic Kirk,Wow!! I have never seen the two bearings side by side,u are correct thats a monster in comparison.Does it also have a thicker wall? I would guess that the seals on the larger bearing are also thicker and therfore stronger which may also help in regards to oil penetration. With regards to the law suit strictly related to autos 01 thru 05 , i wonder if people with 06 thru 08 autos that in time start to have similiar IMS problems.
Will they have less problems making a claim with Porsche now that there has been a documented and proven problem.Based on how Porsche handled this issue of denial over the last 10 years or so,knowing full well that there was an legitimate concern or problem i don,t feel reallly comfortable in purchasing a DFI car with all new technology which may down the road prove to have problems that they will deny until people force them to act!
Raby has already shown pics off excessive cylinder wear on low milage units of DFI cars that werent tracked (probably heat related). Good luck.

[Jake Raby]

I'm not sure I would worry about the size/strength of the bearing in MY 06-08 cars. The 6305 bearing in those cars is a monster compared to the single row 6204 in MY 01-05 cars.

If lubrication really is the problem, then why would bearing size even matter?

[thom4782]

Originally Posted by Jake Raby

If lubrication really is the problem, then why would bearing size even matter?

Great question...

In theory the answer could be that it takes bit longer for friction to destroy a bigger bearing just like it takes a saw a few more strokes to cut through a few more millimeters of wood. In practice, it doesn't matter unless the actual failure mechanism is related to load bearing capacity.

[cnavarro]

Originally Posted by Jake Raby

If lubrication really is the problem, then why would bearing size even matter?

If lubrication really is the problem, bearing size wouldn't matter. But the failure figures of the dual row versus single row IMS bearing from the class action lawsuit tell a different story.

[Kirk]

Originally Posted by moresquirt

Thx for the pic Kirk,Wow!! I have never seen the two bearings side by side,u are correct thats a monster in comparison.Does it also have a thicker wall?

You can see in the picture that the 6305 bearing has thicker races. The width of the 6204 bearing is 14mm while the 6305 is 17mm wide (or what I believe you are calling thick). So yes, the 6305 bearing is bigger all around. It also has bigger balls...

Kirk Bristol

[Jake Raby]

Originally Posted by Kirk

You can see in the picture that the 6305 bearing has thicker races. The width of the 6204 bearing is 14mm while the 6305 is 17mm wide (or what I believe you are calling thick). So yes, the 6305 bearing is bigger all around. It also has bigger balls...

Kirk Bristol

Ok, lets remember this statement leading into the future when discussing the the problem with the M96 IMSB is only limited to lubrication.

If the problem was limited to lubrication, then Kirk's observation and most recent statements would not be relevant, but they are.