Replacing IMS with Original bearing

[Bala]

Has anyone replaced the IMS with the original part? Sorry if this is a repeat. Searched and couldn't find anything. Going to drop the trans and inspect the IMS, RMS and the clutch and am trying to narrow down my options. Have oil dripping between the engine and the trans.

My dilemma is that even with the LN kit, it's no guarantee there will be no failure. Since the failure rate is not clearly documented - original or LN, I'm thinking the IMS guardian would be a better peace of mind either with original bearing (new) or LN one. But since the LN bearing is ceramic balls would the Guardian really be able to catch it in time. Being a magnetic based monitoring system?

Also if anyone has a cost comparison between the two bearings it would be great to know. Thanks.

[Bigsmoothlee]

I was in your position last year, and I went with LN engineering's bearing. If you need a good local shop to change it for you, shoot me a PM

[JFP in PA]

Originally Posted by Bala

Has anyone replaced the IMS with the original part? Sorry if this is a repeat. Searched and couldn't find anything. Going to drop the trans and inspect the IMS, RMS and the clutch and am trying to narrow down my options. Have oil dripping between the engine and the trans.

My dilemma is that even with the LN kit, it's no guarantee there will be no failure. Since the failure rate is not clearly documented - original or LN, I'm thinking the IMS guardian would be a better peace of mind either with original bearing (new) or LN one. But since the LN bearing is ceramic balls would the Guardian really be able to catch it in time. Being a magnetic based monitoring system?

Also if anyone has a cost comparison between the two bearings it would be great to know. Thanks.

First of all, if you go to Porsche, all you can buy in the “final solution” IMS shaft with the bearing already in it; this is the unit you have to disassemble the engine to install. And it is expensive as Hell, more than twice the cost of an LN update unit……. Your only alternative here is the OEM style replacement Wayne has developed, but it is my understanding that he will be recommending replacing it every 30K miles, which will rapidly escalate its “cost of ownership” way outside that of the LN unit.

Both Jake and Charles have been very upfront in how their upgrade has been doing; the last I read was a total of four LN bearing failures out of more than a couple thousand installations. Three of the four failures were suspect (poor installation technique, or the IMS destroyed by debris from a different type of engine component failure), leaving only one that failed for unexplained reasons.

Regardless of the bearing materials, ceramic hybrid or steel, when the bearing starts to go, there will still be a ton of ferrous debris circulating in the engine; so the Guardian will function as designed.

There are no guarantees in this life; engines break for all sorts or reasons, the IMS is only one of them. You could install the best IMS replacement available, and spin a rod bearing the next day. Instead of looking for “iron clad” assurances, you should be looking at an IMS update the way most owners look at oil; you want to get the best possible product in the car in order to eliminate as many possible problems as you can.

[Bala]

Originally Posted by Bigsmoothlee

I was in your position last year, and I went with LN engineering's bearing. If you need a good local shop to change it for you, shoot me a PM

Did you research the original bearing at all. What was the cost difference if I may ask.

As for the shop I'm going to tackle it myself. Though frustrating sometimes it is fun to work on the car. Thanks for the offer to recommend.

[Bala]

Originally Posted by JFP in PA

First of all, if you go to Porsche, all you can buy in the “final solution” IMS shaft with the bearing already in it; this is the unit you have to disassemble the engine to install. And it is expensive as Hell, more than twice the cost of an LN update unit……. Your only alternative here is the OEM style replacement Wayne has developed, but it is my understanding that he will be recommending replacing it every 30K miles, which will rapidly escalate its “cost of ownership” way outside that of the LN unit.

Regardless of the bearing materials, ceramic hybrid or steel, when the bearing starts to go, there will still be a ton of ferrous debris circulating in the engine; so the Guardian will function as designed.

Love it when the answers are spot on. Thanks JFP.

[mikefocke]

Hartech in England is doing original material IMS bearings but removing the inner seal so the method of lubrication is the same as the LN bearing. Installation difficulty/risk the same. Probably much better materials in the LN bearing.

For now Charles is being cautious on any claims of longevity until there are more high mileage examples of the replaced LN bearing returned to he (and Ed, the bearing engineer) for analysis. Their expectation is the longevity will be actually much longer than the 30k. But until the sample gets big enough and the analysis is done, who can be sure.

There is wear and failure in every rotating part. Some fail earlier than others, some later.

[feelyx]

The original mfg. of the IMS bearing was a NSK. The bearing # is 6204 2rs. Email tech support and ask them what is the recommeded lube would be for the bearing in the engine/conditions/temp and rpm of the bearing (1/2 max engine rpm), and how long that bearing will last in those conditions. You could also ask if the ceramic bearing would be better, S6204 2rs. It will take them a couple of days to get back to you.

[Gilles]

Originally Posted by Bala

As for the shop I'm going to tackle it myself. Though frustrating sometimes it is fun to work on the car. Thanks for the offer to recommend.

+1,

And the experience? ...priceless

.

[Bala]

Originally Posted by mikefocke

Their expectation is the longevity will be actually much longer than the 30k. But until the sample gets big enough and the analysis is done, who can be sure.

There is wear and failure in every rotating part. Some fail earlier than others, some later.

Exactly! I would love to put the LN one and be done with it. The 600 bucks is not my concern. I'll still not be at peace unless I put the Guardian to watch over me! So, with the LN really not proven statistically or otherwise I think it's the same risk as the original bearings. At least at this time.

Checked Hartech website and didn't see anything on the IMS bearing. So, sent them an email.

Let's see where all this ends. Maybe when I drop the tranny I'll find that the PO replaced my IMS bearing with a one made of diamonds! Would that reduce the failure rate? Well at least my wife can have a necklace out of the debris!!!

[fivepointnine]

I want to say that even LN is recommending replacement at clutch changes

[berty987]

I read the SKF bearing book on bearing design from cover to cover and bearings have a tendency to fail unpredictably if not operated within their original design specifications. The IMS bearing is of the deep groove design and is designed to be grease lubricated not oil lubricated. If the seals fail or are removed the bearing isn't correctly lubricated and service life becomes unpredictable. The later model m97 engines in the 987 from 2006 used a larger diameter bearing ( so turn slower) than the earlier m96 so the crank case is a different design and they cannot be retro fitted without machining. Personally I think there is no discussion, fit the LN bearing wherever possible , it's not only specified for oil lubrication , it's also better at higher temps. It is not however without it's limitations , as it has lower load ratings and speed ratings than the oem unit , hence the hesitance to stipulate it's 100% guaranteed.

[Bala]

Originally Posted by berty987

It is not however without it's limitations , as it has lower load ratings and speed ratings than the oem unit , hence the hesitance to stipulate it's 100% guaranteed.

When you say lower load and speed ratings what do you mean? Sorry, not that savvy. Am I looking at driving like Grandma?

[Steve Tinker]

Bala...
What berty is alluding to is the fact that ball bearings in general are limited to several factors determining their suitability - some of which are lubrication, rotational speed / loading and temperature.
With the IMS bearing, the "load" is coming from the tensioning pull of the chain(s) operating the camshafts, so I would think that that kind of lightish loading is well within the design parameters of a deep groove ball bearing.
Rotating speeds @ 50% of engine revs (lets say 4,000 rpm max) @ 100 deg C also shouldn't be a problem as long as the lubrication is constant, clean and of good quality - but that of course could be the achilles' heel of this system.
Ceramic composite bearings have excellent wear characteristics over steel (especially in questionable lubrication areas) but do not have as high a load rating.
Roller bearings (where the balls are replaced with cylindrical shaped rollers instead of spherical balls) have a much higher load rating, but much lower speed tolerance, so would be unsuitable in the IMS application.

As a side note, the grease used for bearing lubrication is really only a lubricant enclosed in a carrier to prevent it being flung off at high rotational speeds - the push fit RS (rubber seals) each side of the bearing also helping retain the lube. Most bearings are "filled" with less that 30% grease (if I remember correctly) during manufacture, any more and there is a real chance the bearing will overheat before it can squeeze out the excess...
I'm sure Navarro, Raby and their bearing engineer have had all these bases well covered in the initial design stage, so you don't have to drive like Miss Daisy.....

[Jake Raby]

The IMSG can be co-applied with the ceramic hybrid IMSR bearing. We actually sell a combo of both from time to time.
BTW driving like Grandma is the worst thing for the factory bearing~

[Jaxonalden]

Originally Posted by Jake Raby

The IMSG can be co-applied with the ceramic hybrid IMSR bearing. We actually sell a combo of both from time to time.
BTW driving like Grandma is the worst thing for the factory bearing~

Jake,

The IMSG is a chip detector, an electronic instrument that attracts ferromagnetic particles. Your IMSR bearing is ceramic right? If your bearing fails, how does the IMSG detect it since ceramic is non-ferromagnetic?

[Bala]

Expert please enlighten me. Love to stuff my brain with interesting information.

The IMSR is less load rated than the oem one. It is also less speed rated then the oem one. All the reading I have done from the forum here and advice from previous owners are that These cars need to be driven like grandma on steroids! One seller even told me that at each gear it should be taken upto 6k rpm before shifting. That maybe overkill but i can say that it makes my stupid grin wider. And i dont mean redlining it.

So, am i looking at moving to a conservative driving style with the IMSR compared to oem given load and speed ratings? And also have the same question as Jaxonalden below. These ferrous bit that are present prior to the failure are from the balls or the casing? What actually goes first and lights the fuse? And how do both differ in that process?

[Bala]

Originally Posted by Jake Raby

The IMSG can be co-applied with the ceramic hybrid IMSR bearing. We actually sell a combo of both from time to time.
BTW driving like Grandma is the worst thing for the factory bearing~

Jake,
Do you have any statistics as of this time as to how many have been deployed and how many failed and the causes for failure? Sorry if it has been published and i missed it.

Thanks

[mikefocke]

The LN IMSR had a total of 3000+ installs as of late last year according to Charles. That of course includes both 986s and 996s. Failed bearings returned to Charles are sent to Ed for analysis.

Aren't we lucky to see so many P-car owners working together to come up with the best solutions they can for us.

[Bala]

Originally Posted by mikefocke

The LN IMSR had a total of 3000+ installs as of late last year according to Charles. That of course includes both 986s and 996s. Failed bearings returned to Charles are sent to Ed for analysis.

Aren't we lucky to see so many P-car owners working together to come up with the best solutions they can for us.

JFP said about 4-5 failures. Out of 3000? That is good.

You are right about the owners working together. This collective effort and support is what makes owning this car fun and possible. Without this collective effort (and the members of this forum) I wouldn't touch this car with a 10 foot pole.

[berty987]

I think the big question here is whether it's better to rely on the seals of the original bearing to keep the grease in and contaminants out , or a ceramic bearing relying on clean oil to keep it lubricated.