Pedros Techno DOF IMS fix?

[southernstar]

Charles, I think those numbers confirm what what we already know from the lawsuit: all else being equal, the dual-row bearings are more durable/reliable than the single-row bearings. Based upon experience in other applications, we also have reason to believe that a ceramic bearing should be more durable than a steel ball bearing of the same design. However, virtually all invovled in this discussion (including the LN Engineering site as per excerpts already quoted) also suggest that lubrication of the bearing is PART of the problem.

Kirk, I look forward to your updates. With a failure rate of approximately 1%, I would think that if you had a dual-row bearing you would likely be fine with a new dual-row steel bearing and DOF. With the single-row bearing, however, I wonder if the additional cost of a good ceramic bearing might not provide added insurance.

Brad

[Kirk]

Originally Posted by southernstar

Kirk, I look forward to your updates. With a failure rate of approximately 1%, I would think that if you had a dual-row bearing you would likely be fine with a new dual-row steel bearing and DOF. With the single-row bearing, however, I wonder if the additional cost of a good ceramic bearing might not provide added insurance.

I am not worried about cost. I have both - steel and ceramic bearings in my hands. I can put either in my 2003 C4S. The ceramic would be the obvious choice, right? My only concern there is the nylon cage that holds the balls in position. I have been researching this material to see how well it will hold up in a hot environment exposed to synthetic oil constantly. I see manufacturer's temperature specs ranging from 210 to 250 F. But we know that the bearing seal is rated for 250 F and it does not hold up well. I thought I saw that LN Engineering uses a steel cage, but I have not confirmed that. I know that Casper Labs used a steel cage precisely because the temperature limit of the nylon cage is too close to the hot operating limit of a Porsche engine. So I'm not sure I feel comfortable putting a ceramic bearing with a nylon cage in my car... Still reading and researching before this weekend. One advantage of the DOF is that the better lubrication should allow the bearing to run cooler.

Kirk

[thom4782]

Originally Posted by southernstar

...However, virtually all invovled in this discussion (including the LN Engineering site as per excerpts already quoted) also suggest that lubrication of the bearing is PART of the problem.
Brad

When talking about the oiling question, it's importanty to keep in mind there are two very different situations to look at.

Situation #1: Lubrication is a problem with the 'sealed" OEM bearings. When seals leak and oil mixes with grease, then friction increases and the bearing eventually fails. This seems true for both dual and single row bearings.

Situation #2: After someone replaces the IMSB with an "unsealed" bearing, hopefully a ceramic one, sump oil lubricates the open replacement bearing. As I've said many times, the experience to date shows virtually no failures with this oiling method.

So context really matters when talking about lubrication as a problem no matter who is commenting.

[Jamesp]

Nylon seems to be a poor material choice for the operating environment the bearing will see. Personally I would shy away from using it in this application as the risk associated with its failure seems greater than the benefit of the ceramic materials in the bearing.

[southernstar]

Thom, if you read post#48 you would see that I do, in fact, talk about both methods of lubrication. And Kirk, was the ceramic bearing that you have purchased in conjunction with the DOF? Frankly, I share your concerns about the durability of the nylon race, even with the improved cooling that should come with DOF.

Brad