LN dual Row questions

I am trying to make my final decisions on the IMS retrofit. I want a dual row so my choices are repacking/sealing and putting my old good bearing back or put the LN bearing in. The LN bearing is shorter than the stock bearing which has a retaining clip built in. The LN kit has a spirolock to hold the bearing but no other spacers etc. In my mind this will leave a small gap between the flange and the bearing..? I bought the Pelican single kit that has a thousand spacers etc. although I have no intention of running the single. Can anyone who has installed the LN dual row explain how the bearing stays in place? Is it just the spirolock and that's it leaving a gap? Also how does the new stud seal without there being a groove. Is it just a pressure/sandwich at the base of the stud? i am just so overwhelmed by info and options. And since ordering the LN pelican single kit I am less sure of anything than before. Below is a borrowed image (side by side of the oem left and the LN right...

You may get a lot of differing opinions on this, but mine is pretty simple. I selected the LN single to dual row retrofit and had a trusted indy shop do the work as a preventative measure. I selected the LN option as it seemed (to me) to be the most proven replacement for my 2004 single row bearing. It made no sense to me to go to the trouble to remove a proven poorly designed stock bearing, service it, and then reinstall it, and then continue to wonder about its lifespan. My understanding is that it isn't the dimension of the housing that is the important factor, but rather the use of ceramic ball bearings that have a higher level of durability. Please keep my comments in perspective, I did not do the install, but relied on a trusted shop to guide me and do the actual work. If I have presented some inaccuracies, please just ignore me.

Decisions you say... I bought a '99 c2 cab. going on 9 months ago that had 60K miles on it. Other than a son-of-a-bitch idle issue which turned out to ultimately be a bad wire in the harness to the throttle position sensor, the car runs and looks great. Here's the fun part... So the first owner bought it in '99, then sold to the second owner in early 2004 with 18K miles. Second owner had the dreaded oil/coolant intermix in mid 2004 at 22K miles. It was out of warranty, but Porsche replaced the engine and only charged him for labor. Nice. This second owner then drives the car the next 12 years until I buy it last December with 59,732 miles. That's ~3,200 miles a year and oil changes were done every 12 months with Mobil 1 0w-40 religiously. And I have all the records showing this. Along with very excellent PM and servicing records over this 12 years. So that means I know this engines history since it was put in the car and other than (splitting hairs) wishing the oil was changed every 6 months and with perhaps Joe Gibbs DT40, what is there to not to like? I've spoken with the dealer that installed the new engine and I have the receipts listing the work, BUT, there is no way to know what IMS bearing was in the replacement engine. As most of you know the original engine most certainly had the double row in it cause it is a '99. But the replacement engine which was pulled out of inventory at Porsche and installed in 2004 has what bearing? No one knows. So that's the decision I am left with, knowing all this... ...to replace or not to replace, that is the question....

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Can't you contact LN and ask them?

Went LN Dual Row. Had an Indy install. Leaked after 11 months. Replaced with the same LN dual row under Indy/LN warranty. No issues after 9 track days/6 months so far.

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pushes me to...."if it ain't broke don't, don't break it"

I was hoping to gain some first hand knowledge, And a basic understanding. I do not have the option of having a shop do the work, qualify the engine or the like. The pelican kit has some LN parts (center stud, seals, etc) and is supposedly meant to retrofit a single into a dual row car. It requires a total of 4 spacers to make this setup work. The LN dual for dual has No spacers or ring sealing spacers or anything. Yet uses the same center stud and seal? It also uses a shorter than stock bearing, so I just don't understand why one kit requires a bunch of spacers to make up the space and to make the new shaft o ring seat and the other kit uses none.

Tough decisions to make. I'll throw one more thing in the mix - it is my understanding that once the bearing is pulled it should not be reinstalled, ever. The business of pulling out the bearing basically ruins it forever. I think you should contact Charles at LN and specifically ask him your questions. He has been very responsive both in the forums and contacted by telephone.

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yeah I just read that. Something about damage to the races. LN's website even says that if you have to remove their bearing to re-install you have to buy a new bearing.

It blows my mind to see the amount of people fall for some internet bs pull apart a perfectly fine engine, only to call it PM.

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Well I feel like this has some truth. Do I think the bearing problem is BS? No. Do I think that I should have left mine alone? Yes. If I could give any advice to people who may have higher miles like I do I would suggest pulling the seal off the bearing and inspecting. Prior to removing. I am now stuck trying to decide what solution I can trust for apparently the next 50k?

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^^^^ This The sad part is that in 5+ years the unmolested factory 996 will be worth more than those with hacks created by profiteers. Wait and see...

You're in there now, so bite the bullet, write the check and get the LN Solution(pressure lubed journal type). That's the last and best word on IMS bearings now. While I don't fully agree with the sentiments about leaving things alone completely, I somewhat agree that a bone stock early car will have a market advantage provided the seller can prove the IMS is not headed south at time of sale. This would be a car with full flow filter, a chip detector in the drain plug, regular oil changes, and of course a full pan off inspection during PPI. I bought my 99 with full intention of ripping it down and doing the IMS within 3 months. Then, the more I thought about it, the more I was convinced that the dual row bearing with proper care will hold up. I have the full flow filter and chip detector should things go south I am guardedly optimistic that I can save the engine should the bearing fail in it's typical mode. Of course, it it explodes while under load(very rare), I'm a dead man.

I'm of the attitude, if my car goes, it goes and I will buy another one that looks just like it. With that being said, I still take care of my stuff, but I'm not about to do major surgery on something with a less than 1% failure rate.

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porsche admitted it was higher than that. they also got sued and lost. there's more truth to it than you'd like to admit.

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If I were a seller not sure I'd sign off on having the oil sump plate removed during a PPI. That's a bit too invasive for me. The oil has to be drained. I'd worry about what is used to catch the oil as I'm pretty sure the PPI would want to save this oil to be put back into the engine. Then there is the resealing process. Who pays if this leaks if the car doesn't sell to the buyer who had the pan dropped? And what about subsequent buyers? The pan drop is worthless to them then. If the IMSB was bad enough to put large bits in on top of the oil sump plate the IMSB would be making scary noises or already be in pieces during any reasonable test drive. And what's to prevent the seller from doing this *before* he puts the car on the market?

I have reached out to LN for some clarification. I didn't want this thread to get sideways. I really just wanted to know if anyone could answer the original questions.

Anyone fortunate enough to buy a car from Macster should just write the check ! If in doubt they should read just 1% of his thousands of posts for confirmation .

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Not sure if your questions are rhetorical or not, but in case they aren't, then here's where I stand. If the seller will not let the pan be removed by a pro Porsche shop for inspection, move on to the next car for sale. If you are sure the oil should be put BACK in the car once it was removed, then you don't know much about an oil change. There is no way I would ever put used oil back in the engine once it was drained, unless it was drained into a surgically clean bucket, and then strained through a small grain no-fiber cheese cloth back in the engine. Sane people would simply put new oil and filter on. Again, if you have a Porsche pro R&R the oil pan and it leaks, take it back and have them seal it properly. I don't care about subsequent buyers, I care about me. I'm paying for a car, and a PPI, I'll get what I want, or move on. Nothing prevents the seller from doing what I want done. There are no iron clad guarantees in life except death and taxes. This is a reasonable method for detecting a defined failure mode. There will always be ways to cheat the next guy in line buying a car, and I guess unless a person stays in bed with the covers up to their neck 24/7/365.25 in a stew of feces and **** there is going to be some risk. Mitigating it with reasonable precautions is all I can offer.

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"The LN bearing is shorter than the stock bearing which has a retaining clip built in. The LN kit has a spirolock to hold the bearing but no other spacers etc. In my mind this will leave a small gap between the flange and the bearing..? I bought the Pelican single kit that has a thousand spacers etc. although I have no intention of running the single. I think you are confusing the 3 types of bearing ? Suggest you avoid spacers. The spirolock works perfectly. There is no gap Can anyone who has installed the LN dual row explain how the bearing stays in place? Is it just the spirolock and that's it leaving a gap? Also how does the new stud seal without there being a groove. Is it just a pressure/sandwich at the base of the stud? i am just so overwhelmed by info and options. And since ordering the LN pelican single kit I am less sure of anything than before" Are you fitting the new bearing yourself ? Or is an Indy doing it? I ask because that answer will whittle down the options.For example the LN "Solution" is a pro-install only item - not a diy option. Let me try to help. First - forget the Pelican part with spacers.I order lots from them,they are my favorite supplier,but not this part imho. Second - use the correct full name of the part and identify the differences.The LN 'dual row' you mention - do you mean the staggered 2 row bearing or the conventional double row ? If you mean the Gen 2 Single Row Pro - say so and you'll get much better answers(than this one :-) ) Third - have faith - in the numbers ,not individual advice (like mine) . We are biased. But the statistics are overwhelming in supporting the LN products. You will never regret using LN in my experience and you'll never need to make excuses for fitting their parts. Disclaimer - I did not buy a Gen 2 Single row Pro(was not available - damnit!) I do own some LN tools (gift from P.O.) I have not spent any significant money with Jake or Charles but they have both helped me with generous technical advice. IMHO they are both either kind fools or Saints ! Try to get a recommendation of a qualified Nashville installer from LN and visit a few. Ask here also. Let us know what you do and why ?Good luck and enjoy the car ! And don't forget the RMS replacement while you are in there if it hasn't been upgraded. I hope this helps you make a decision.Ignore the rant -type responses -see bias comment above.It is just noise.

>>I'm not about to do major surgery on something with a less than 1% failure rate. If swapping out a bearing is "major surgery", I wonder what category a new clutch falls into. Seems like 'replace the bearing with the clutch' is the emerging "wisdom" on this silicon-accelerated Porsche panic. Can't see why original IMS bearings would be a big value driver on these cars, any more than original studs help midyears, original tensioners help "long hoods", or original seals help 964s. It's *hilarious* to me that the IMSb is treated like the first (or biggest) fly ever to besmirch the exalted engineering purity of the 996. Weak links, factory and aftermarket fixes, debates, indignation, factionalism: It's just another Porsche 911 .

"Second use the correct full name of the part and identify the differences.The LN 'dual row' you mention - do you mean the staggered 2 row bearing or the conventional double row ? If you mean the Gen 2 Single Row Pro - say so and you'll get much better answers(than this one :-) )" this is might as well have been French. I only saw one dual row for original dual row cars on the site. Add to the confusion.

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I'm sure LN can clarify. My understanding is the LN flange is made deeper to take up that "gap" you mentioned to hold down the inner race of the bearing. The o-ring has been relocated to the inside of the flange to seal the groove-less stud.

03 C4S WITH 10k miles. I just did have the LN single row pro installed. my low mileage was the factor in changing it cause the car just wasn't driven enough before I bought it. Indy said the bearing had more play in it than a 10k mile car should. Not that it was ready to go, but now I have piece of mind FOR at least 6yr or 75k miles. Lots of chatter about IMS issue which really creates the hype, so if your on the fence just get it done. Go to the LN site and see what they have.

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It is all very clear on the LN site. http://imsretrofit.com/gen-2-single-row-ims-retrofit/ Forget the older Single Row Pro. Focus like a laser on "Gen 2 " It would help you if you identify which bearing is fitted to your car. Single or double? This is a sequential decision process.If you start in the middle without the basic info -it is useless.Unless we know if your car has a single or a double ,it is difficult to be specific.

A 1% failure rate is horrible for modern common mechanical components. Toyota would not accept anything close to that. Particularly where the failure causes catastrophic engine damage. Even 0.1% failure rate is wildly out of range. So, if the actual measured failure rate was somewhere around 5-8% for single row, that's an egregious mistake. I'm not trying to sound like chicken little with the sky is falling, but the market has spoken on these engines, and spoken loudly.

^^ but that doesn't factor in the age of these cars. 1% failure on cars over 17 years isn't the same as 1% failure rate off the lot. Given enough time and usage, all parts will have a 100% failure rate

^ Well, I appreciate the 'correction' but being a fan of stats this is one of those relativistic statements. If we take enough time in the equation, all failures eventually reduce to 100%, true enough. Most modern cars are expected to not suffer catastrophic engine damage at a 5-8% rate within 100k miles or 10 years or so. Again, stats back this up with all car vendors carefully monitoring the failure percent. Why? Because they are somewhat concerned about lawsuits like the Porsche class action. Further, with this type of failure there's no saving it beforehand. Compare with the Cayenne, when the coolant starts to drool out of the crossover pipes, you get 4 warnings. Low coolant sensor, check engine, visible leaks under the engine, and finally high temp alarm. Any of these can save the engine from catastrophic failure and give the owner time to solve it prior to a $20k bill. The IMSb is like a little mostly silent time bomb(unless one has a chip detector), which goes from zero dollars of maintenance cost to $20k do-over almost instantly.

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I'd get a magnetic oil plug, switch over to Joe Gibbs DT40 as you suggested, change oil every 5k or 6 months, inspect filter for debris and maybe consider an annual Blackstone oil analysis. Then when clutch time comes get your new bearing then.

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Sorry. My car is a 1999 with a dual row. I really don't want a ceramic upgrade etc just a stock style replacement.

See the post above from Porsche 951.That is all you need to do.

I have made a mistake. I thought the OP was already in there, with the bearing in hand. Seems to be in error. Given that, I agree that using a mag oil drain plug, and a full flow oil filter, change oil regularly and leave it as is until such time there is need to go in.

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Not on the 99's

RRTEC said"Although I have since ordered new lifters while I have my engine out for other repairs " - in a 'ticking noise' thread elsewhere. We are getting half the story in garbled pieces.Oh ,and Seafoam fixed it ! https://rennlist.com/forums/996-foru...6-ticking.html

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I'm not really sure what you are getting at? I have a lot going on with my car. I pulled my engine due to intermix. Had the head rebuilt and am doing all other preventative maintenance while its apart. That other thread is unrelated. Geez.

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I am already in there. My bearing is out...

OK, then install the LN Solution(journal type) and be done with it. You are investing in other parts of the engine, and consider leaving the stock IMS time bomb in there?

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the stock IMS is out. All I really wanted is a stock replacement. It lasted 108k... If that isn't possible then I want a dual row for sure.

I understand the LN Double Row Solution is now available. Now that would spell: Piece of mind!

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To me, it's rather shocking that the problem got worse, not better, with each model year of the 996. I'm definitely getting my 04 into the LN solution ASAP.

No, the bearing width is properly adjusted for the retention circlip. Just install it, all those physical differences are a non- issue, and have 20,000+ installs under their belts.

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I hate to keep perpetuating this thread, as it seems it has been answered, but WHY would you want to put another stock, proven poor design, back into your engine when there are other proven improved designs available? Your engine is already apart, you need to purchase some part, why not purchase the improved design?

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Also, there's no OE IMS Bearing... Not even a part number for one. Never has been. The factory never intended for the bearing to be removed. That's what drove me to do it the first time. Again, you have NO factory IMS Bearing option.

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the reason for the desire is my bearing is in good shape after 108k. Never been swapped. I like that service interval better than 50-75k miles... I am buying the LN it seems, thanks all.

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The 75k service interval for the dual row bearing is just that. It doesn't mean the bearing will fail at 75k miles, but rather that it has reached the service life for the application based on operating hours. The factor single row 6204 bearing with inverted race operation is only 1500 hours. If you want to do this once, then install the IMS Solution and there are no more service intervals.

This specific case reads as if it would fail pre-qualification anyway.

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75k miles could be a range of operating hours, depending on speed and traffic, right? 75 mph average would only be 1000 hour operating time? Do you do an average speed to get the 75k figure?

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To find the average speed of one of these cars look at the operating hours logged in the ECU, then use that figure to divide by the mileage that's on the odometer. This will give the average speed of the vehicle over it's entire life. I do this with every car we see, and log the data. Cars that are driven in the city will see an average MPH of 25.5-28 MPH, those that are normally driven with street and highway miles will be between 28-33 MPH, and those that see a lot of freeway driving will usually be 33-36 MPH. If I see a higher speed than 38 MPH average, I know the car has either lived its whole life on the open road above 80 MPH on the freeway, or it has been to the track a good bit. The highest average speed I have ever recorded from a street car was 43 MPH and that came from a car that saw its whole life on the freeway in Texas. Keeping these logs help us watch the way that customer's drive our engines compared to how they drove the car before we built the engine. It also was the main factor in determining the recommended mileage intervals that the IMSR products should see, based from their recommended hourly service intervals. Cars spend all their time going 0-60 more than anything, so to have averages in the high 20s to low 30s is the absolute norm.

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Very informative- thanks Jake!

Wouldn't it be wonderful if Vertex joined this interesting discussion and shared their data and experiences of durability testing?