DrMEMS

@Jake: My old engine is with your friends at MB Motorsports.

@Charles: You said "At no point was LN Engineering contacted to even discuss this..." Actually, I called LNE in February after I had found metal in my oil and was trying to figure out what to do. As I mentioned in my initial post, I called again last week and the technical person didn't have anything helpful to say.

I think you have some great products. I am using your magnetic drain plug and spin-on oil-filter adapter. I would be glad to have the IMS Solution and Nickies cylinders. However, the ceramic IMS bearing didn't work out for me in the worst possible way.

Everyone: Please keep the posts useful to the 996 community. I have no intentions to flame anyone; I am just stating what I believe to be the facts. https://rennlist.com/forums/images/smilies/smile.gif

Note that on the 986 forum there was a post where Agnes at MB said that they referred a potential customer to Jake for the IMS Solution rather than their roller bearing.

alpine003

I read the thread too and Martin also said that he too would use the Solution for his own personal car if he wanted a permanent solution.

However all of this might be a moot point if what Jake is saying about everything being centered is true. I can see a future PPI being invasive and consisting of a center measurement as part of the process.

Now there'll be a lot of retrofitted worry warts losing sleep once again. Lol.

WalterRohrl

My car had one of the engines that had had a problem with the bore. "Intermediate shaft bore out of round by 0.07mm" (from the technician's notes). The car had had a history of chronic RMS and IMS Flange leaks since it was built with the tranny out at least half a dozen times per the receipts. The real issue was finally discovered after the prior to me owner bought it and the car was going through its CPO checks. The engine was then swapped out with a reman'd one, no issues since (knock on wood).

Oh, the notes also stated that the tech actually split the cases to measure it. He was directed to do so by the factory.

wildbilly32

Ok, not an engineer nor engine expert...could the "misaligned crankcase bore" be the real smoking gun in the bearing failures? Or at least a contributing factor? Is this typically measured prior to installing a replacement from a failed bearing? Could this be why some cars run "forever" with no problem and some do not?

Flat6 Innovations

Until my tool development, there was no way to check this dimension.

WalterRohrl

Not an engineer either but my car (the one that had the engine replaced due to the bore being off, two posts up) was at 58000 miles at the time, the only issues were leaks, there was no mention of the bearing being bad. Presumably it wasn't about to fail either (but who knows), so in any case it lasted a lot longer than some others. My car's symptoms were repeated leaks at the RMS and IMS flange after multiple replacement and updated parts.

wildbilly32

so... wouldn't an "out of round bore" be a completely different issue than a "misaligned bore"?

WalterRohrl

I'm not sure but someone can probably enlighten us. It may mean the same thing, I'm only transcribing what was written on my work order / receipt. But on the face of it, to me out of round generally means oblong - and misaligned generally means it is the correct size/shape but not placed in the correct position.

But like I said it may mean the same thing in this case, unfortunately neither the tech nor the engine are available to ask. What matters to me is that the factory did the right thing and stepped up with a new engine without being asked to. I was pointing out my experience in order to mention another issue with some (or at least one) engines.

JD ARTHUR

I am assuming Jake has been aware of this for some time. I am assuming the tool he has designed has been in his hands for awhile even though the patent has not been issued yet. I am assuming that if he found an off center bore he would not install a new bearing unless he could correct the problem or he would be setting himself up for a failure. Lots of assumptions, hopefully Jake will chime in.

Flat6 Innovations

What we are talking about here is the distance between the crankshaft (which drives the IMS) and the IMS housing bore (which holds the IMS flange, thus centering the IMS Bearing).

This distance can be too great, not great enough, or perfect. The challenge has been to determine the perfect distance for the measurement; because its all empirical data, as the factory gave us no mention of any of this.

When I saw the localized erosion of the inner race of the OP's retrofit bearing, it screamed that the instance was aggravated like many I have seen before that were in process failures of OEM IMSBs.

A pre- qualification that we do here includes this measurement; but until I developed the tool others could not easily measure these distances and alignments. That said, even if they could, they would not know what was a good or bad value.

As we learn more and more about this things get better and better. Meanwhile, the other guys sit around coming up with things we already had (years ago), and they are only concerned with sales. They tell you what you want to hear, and their hands stay clean.

Spokayman

So I gather from what you have been posting on this thread that you suspect that the OP's engine had an IMS shaft that is out of tolerance leading to early bearing wear.
It does make sense that a misaligned shaft's bearing would wear unevenly due to uneven application of forces. And such a theory would fit with the inconsistent nature of the IMS problems.
IE, some engines have problems, often at relatively low miles, while other engines never have a problem.

But, if misalignment or a tolerance problem caused the OP's LNE Retrofit bearing to fail, why did his original bearing last so long? The original bearing lasted longer than the LNE bearing and was showing no signs of failure when it was changed out.

gnat

A few things jump out at me here:

1) The OP has a very short posting history.

2) The failure has been diagnosed by Martin's shop who (while denying it) has made it obvious that he has a bone to pick with Jake.

3) Metal debris is found on the magnetic drain plug AND in the oil filter, but the OP decides it's fine to fill it back up and drive another few hundred miles? Seriously? Why the hell did you install that plug if you are going to ignore what it tells you?

4) No mention is made in the OP of an apparently significant accident in the same time frame, this is instead found by the RL Detective Corps.

5) An incendiary thread title that implies the LN bearing is at fault.

I could be totally wrong, but this reads to me like another bad attempt to attack Jake and the LN products (the "I like LN products and respect Jake" comments read like the "I'm not a racist, but..." opening line).

Flat6 Innovations

I agree that the subject line is very suspect.., But when you are at the top of the food chain, you have a target on your back. We are used to that.

That said, the point about the original bearing lasting is a good point IF the misalignment does exist. I have also considered this. We do now know if the OP registered his OE bearing with LN by sending it in, if he had we could look at the data base to see if it had any localized wear when it was disassembled and inspected.

I merely noted the localized erosion of the inner race (the one that is stationary from the moment it is installed) and picked up on the issue as I have seen it play out before. Localized erosion is always aggravated by something.

Why I do so much with this failure, is because it intrigues me. All the dynamics and variables that lead to issues are never ending.

Agent Jester

"3) Metal debris is found on the magnetic drain plug AND in the oil filter, but the OP decides it's fine to fill it back up and drive another few hundred miles? Seriously? Why the hell did you install that plug if you are going to ignore what it tells you?"

THIS....

gnat

You have indeed turned what may have been intended as an ugly thread into an enlightening one, thanks as always.

In your opinion, how long would it take for the misalignment damage that is shown to occur? Could it be that this rear-end collision caused something to happen internally and this damage occurred over the "hundreds of miles" that he ignored signs of a problem? Seems unlikely from my layman's point of view, but it could explain why the original lasted so long compared to the new one.