IMS again
 

This has been discussed to death in various forums but I'm looking for a fresh look at the problem. I have a 1998 and I do question the current findings.

If the bearing was underrated, then all IMS bearings would fail at roughly the same point but they don't. The figures I have seen are 1% of the older cars and 8% of the newer ones. However some cars do +100K miles and no problem. I don't believe that that IMS bearing is underrated. It is highly loaded but within spec. It could have been designed better, however, its not the problem.

There has to be some other factor causing the failure.

Here are a few that I'm thinking of

1 Could a low oil level reduce the oil to the bearing

2 Could it be either high or low RPM be a factor, ie slow town driving or many track days

3 As time has gone on, the zinc, (high pressure lubricant) in oils has been reduced to save the catalytic converters. Maybe other suppliers of oils could have a lower zinc contents. In my vintage race bike, I went through rockers quite regularly till I swapped to a high Zinc oil. Problem gone.

4 were the cars were driven in the odd high temperature days and the weight oil was therefore below the recommended value.

5 Oil does break down over time and changes its viscosity. Were the oil change intervals extended?

6 were the cars standing for long periods of time ? Oil dripped down thus when started the bearings were dry.

Keen to hear other peoples opinions.

Some reading

https://www.timken.com/pdf/5892_Bearing%20Damage%20Analysis%20Brochure.pdf

Spent years chasing 2 stroke seizes till I read this article.

http://www.marshland.co.nz/ftp/Files/topend_rebuild6.pdf

Basically all seizes are oil failures.

Cheers Wallace

Hi Wallace. You're basing all you scenarios on the oil, but the oil level, quality, viscosity, etc should have no 'bearing' (pun intended), because the bearing is sealed and has grease in it.

One thing the oil CAN do over time is become acidic and break down the seal and eventually wash away the grease.

From what I've read, lubrication is the major factor, but it has nothing to do with the oil level or viscosity, it has to do with the bearing losing its grease. Which is why some solutions use an open bearing and constantly pump oil into the bearing, whether it's from an external line or through the IMS tube itself.

Hey, we need to rehash a subject that must have been discussed hundreds of times on this forum already. And thousands of time on all the Boxster forums taken together. Then add in the 911 forums...

I'm with Mike on this..... I think I could probably find 5 posts online SOMEWHERE that read nearly word-for-word like the post below.

You're "keen to hear others thought"? Probably not too keen, or you'd have read then already. Your post rehashes a line of thinking that's been argued dozens of times just in the 2 years I've owned my car. Don't know what'd make your query any different?

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I agree with Mike. However on another note, Mike, which tires do you recommend and which oil are you running? I can't find anything online.

Sorry my mistake. I read about several suppliers with oil fed solutions and never having worked on a motor, didn't realize it was a sealed bearing. That eliminates a huge number of issues.

There are however many sealed bearings that last virtually forever. If so few fail, then it could have been a batch problem from the supplier.

This discussion however made me rethink 'hope it lasts' option to and oil fed solution.

Thanks for the input.

And now for those tires and oil, I will !!!!!!!!!!!!!!!!!!!!!!!! Ha Ha

Yeah, the oil-fed solutions are changing the bearing to an open bearing, which requires constant lubrication. (iiuc)

For me, I wish someone would develop a replacement bearing that's more like a traditional crank bearing, with a direct oil feed to it, and bearing "shells". This makes so much more sense to me, and would have the happy benefits of still staying largely "in-place" if the bearing failed, si timing remains close, meaning no other parts in the motor get damaged. It would also be easily replaceable if damaged.

But that would be FAR too easy for the Porsche community.... Haha. I mean, it'd be almost sacrilegious to put a simple and robust bearing in a motor with 5 chains, all those ramps and hydraulic tensioners, the craziest Air/Oil separator system I've ever seen.... etc etc.

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It's already been done, sort of, but it still uses an external oil feed:

IMS Solution – The only permanent fix for M96/M97 engines intermediate shaft bearing problem

I love how they call it the "Permanent fix" but only guarantee it for 5 years!

You can always buy a 987.2. The IMS bearing in those are guaranteed for life. In addition, I will personally guaranty it.

haha! What I paid for my 986 plus the cost of another motor, if I should ever need one, is still less than half the cost of a used 987.2

So when you (Your significant other) puts a new roll of toilet paper on the holder, is it spin towards the wall or away from it????

I'll bet you can't search that here

There are several IMS kits which provide roller bearings which use pressurized oiling.

There is a kit using a plain bearing similar to the one on the other end of the camshaft and this kit adds pressurized oiling (The Solution).

I think the roller bearing is a disaster, regardless of pressurized oiling.

I'm talking about a plain bearing.

https://uploads.tapatalk-cdn.com/201...8894c8b14a.jpg

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You just described the IMS Solution.

As I wrote in post #8, it's already been done.

IMS Solution – The only permanent fix for M96/M97 engines intermediate shaft bearing problem

Plain bearing.

They call it a "permanent fix" but it's only guaranteed for 5 years! HA!

And exactly how long did Porsche warrantee the car originally?

Away from the wall. I don't want the inaugural application to be with paint, wallpaper, tile, or cement.

To my best recollection, Porsche never made the claim that the car will last forever, or that it's "the last car you'll ever need."

My point is that if they make the claim of being the "permanent fix", they should put their money where their mouth is and guarantee it forever.

Porsche didn’t call it the “Permanent Vehicle” or “Transportation Solution”, suggesting that the car would never fail.
The “IMS Solution”, however, does suggest that (with a 5 year warranty).

Calling something “permanent” or the “solution” without the data to support it is deceptive, at best.

Let's see: Porsche sold you a $50K+ car (original price depending upon the year) and gave you a "limited" 4 year warrantee. LN sold you a $1K part, and warrantied it for 5 years, in a market where 1 year parts warranties are rare, and 30 days is more the norm. And you are complaining?

Cool.
I can't tell from their literature if it's replaceable bearing shells that can be replaced as maintenance items when doing a clutch, for instance?

And, I find this bold type.... interesting:

"DESIGNED FOR THE LIFE OF THE ENGINE. 5 YEARS / NO MILEAGE LIMIT WARRANTY"



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The IMS Solution solid bearing is designed to go the life of the engine, we have never seen or heard of one failing, or wearing out. We are aware of a couple that have been pulled out of one engine (having suffered dropped valves or rod failure) and then reinstalled in another engine where they continue to serve without problem. No other IMS retrofit can be reused.

From conversations with those more in the know, they have no designed life expectancy.

I'm not complaining. I just found it funny they claim to be the "Permanent Solution" yet their warranty is only 5 years. Contrary to your belief, many auto part manufacturers offer a lifetime warranty. Even Advance Auto brake pads and calipers come with a lifetime warranty. Carquest Alternators and A/C compressors have a lifetime warranty. etc.etc.

If they want to claim it lasts forever, then guarantee it forever. It's that simple. Put your money where your mouth is. Just saying.

I don't have anything against the product itself, I'm sure it's fine. I'll probably never buy it though, because for me the cost-benefit analysis isn't favorable.

And BTW, same thing goes for the EPS solution.

Help me understand why no other IMS retrofit could be reused. Thanks.

It has a 5 year warranty because it’s aluminum and does not have a replaceable sleeve.

For a $1500 part with no moving parts, and “Designed for the life of the engine”, I would expect nothing less than a lifetime warranty. ;)

With a roller bearing or ball bearing, you risk damaging the races in removing the bearing. High risk. As in, it'd be REALLY hard to NOT damage it.

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Shame that they aren't using a replaceable bearing shell. That'd be so much easier, too, since one could mic the parts and buy the right thickness for the parts you've got.

Shame.

And I agree: "built for ther life of your engine" should come with lifetime waranty. Otherwise, I'd change the tag line to "built to last you five years".

?? Pfft.

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That makes sense, thanks.

All warrantees are just insurance policies that are factored into the price.

True. So when they sell a part that probably costs $20 to manufacture for $1000-$1500, you'd think a lifetime warranty would already be factored in.

With ball or roller bearing types, the extraction process literally jams the bearings into the race and cages, damaging both. The cages in particular tend to break up and the races get dented or scored due to the force exerted on them. Once this happens, the bearing is going to fail if reused.

Thanks! Makes sense.

This is also why retrofit kit manufacture's have always said if you get an install cocked and stuck, and have to remove it, do not then re install the retrofit bearing as it is now damaged. This was particularly an issue with single row bearings which tended to do this more often than the dual row bearings. This is one of the reasons Jake released his "Faultless" tool system, which prevents getting the bearings cocked during installs.

IMS again... or not???
My 2001 Boxter Base had IMS done 90.000mi ago (then 60.000mi on odo) with this part: 996.105.017
Can I find out from this number if the bearing is single or double row IMS?

Are these IMS bearings items that needs to get done every so often or only to replace the factory original with updated one?
If these need to be canged contionously as a service, I guess it's due in my car now...

Part is listed as a housing. with engine numbers. So I wonder if it was really a bearing change.

Part is listed as "housing". Commonly called "flange". So how do we know if a bearing was changed?

Good question. I have from previous owner the receipt of the IMS bearing and change - clutch change was done also reputable shop, both at the same time. They took pictures of the job as well that shows bearing to be pulled out and also other works that was done... this in consideration, I do trust that it ws done...

Related to the Flange only on this part number, it shows on the invoice as "996105017 IMS bearing kit, Porsche Boxter 97-04" at 750€ price. Price for the work was as a separate line item.

After reading much more on this subject and trying to sort out any 'warnign signs' of wearing out IMS bearing, I can't find any warnign signs commonly written about - besides the current IMS bearing mileage.

I just had the LN IMS Retrofit done on my 02 Boxster S at 115,000 miles. When it came out the original IMS bearing was, in a word, perfect; it was in like-new condition. Still happy I had it done.

I intend to do the same thing in the spring on my 00' Carrera with only 34,000 miles. There are zero signs the car needs it; oil change at purchase showed (when the old filter was cut open) zero particulate inside, and the car's been dealer serviced regularly. Nonetheless it'll get done.

It's a really simple equation.

1. There's a (low) failure rate of some number with these bearings, and there's no accurate data on what percentage will fail. There's also no accurate predictor as to which cars are going to fail (high miles vs. low miles, single row vs. double row, oil changes at X miles vs. Y miles, etc.)
2. The vast majority of IMS bearings won't fail (as evidenced by mine, which was a single row in great shape after 115K).
3. Resale value of cars with IMS bearing replacement is higher.
4. Having the bearing work done eliminates "not knowing" how your bearing looks. That in a nutshell is why I did mine and why the 911 will also get the work done. Simple peace of mind.

There's a lot of subjectivity, and there's no right or wrong answer. If someone decides not to replace their bearing based on the low failure rate, clean oil filters etc., that's a pretty good plan with a high chance of success. And if someone (like me) decides to go ahead with replacement based on the certainty a new bearing provides, well that's OK too. Do what works for you and enjoy the car.

Thanks Subman, good points. I'l probably get the IMS bearing changed at the spring as I get the car out from the garage (currently hiding from the snow) ;)

Subman makes some good points, but consider the cost vs benefits. You can get a good used 2.7 motor from $1500-3000 depending on location, miles, etc. An IMS will cost you around $1500. So you're looking, at best, at a 2:1 insurance policy against, at worst, a 15% chance the IMS bearing will actually fail.

Is it worth it?

I have a 2002 with 93K miles and Tiptronic. If I had a manual and needed to change the clutch, the IMS bearing may have been a "while you're in there" sort of thing. I don't, so it's not worth it for me.