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IMS again - sorry

adamw

Well-known member
Joined
9 Jul 2009
Messages
4,339
Hi guys
As allot of you will be aware I recently acquired a lovely 996.1 C2 (marky911's old car). Being an early car {98} this has the dual row bearing fitted and the car is on circa 70k miles.
Part of the reason I wanted an earlier car was the dual row bearing as if read that this was known to be the more reliable solution in the 996.
The cars been extremely well cared for with regular oil changes and any work needed.

When purchasing the car I was asked by the garage that inspected the car (PPi) if the IMS had been changed? My answer was that it hadn't and I didn't intend to because of the more reliable dual row bearing. I was advised these still fail (which I know) but thought the risks were lower.
The thing is, this has now put a doubt in my mind.

This car had a new clutch circa 2k ago and Mark got the IMS checked at the time and was advised it was found to be silky smooth with no play.
At this time the cover was flipped off (Hartech advice) to allow fresh oil to get in and the original bearing was left in.

Now, I know there are aftermarket solutions (LN and EPS etc) which I've done some research on.
* LN ceramic - Not sure on LN ceramic as this isn't a perm fix and i think failures have been reported (correct me if I'm wrong).
* LN 'soliton" - silly money (Over 2k plus vat) just parts and I'm not sure of the reliability of this really.
* EPS - I liked the sound of this cylindrical bearing but when I dug a little deeper read some negative reviews about 'thrust pressure"

Trouble is I'm not sure there is an after market solution that truly 100% mitigates this risk ???

Question is do I :

A - Stick with the existing dual row that was checked and confirmed in good shape 2k miles ago and stop worrying

B - Do some more research and look to pay out for an aftermarket 'upgrade"

If B, any suggestions or comments would be most welcome.

I asked the same question on x2 Porsche Facebook pages:
* A global Porsche page where the responses were mainly from people in the US saying fit LN!
* Porsche owners UK where the consensus was mainly leave as is!

Now im asking the experts - 911uk

Thanks for listening guys and input much appreciated

:thumbs: :thumbs:
 
Mainly a UK group, you know the answer...
MC
 
Hartech are the experts. They recommend exactly what Mark did (and myself too) unless you want to go down the route of a rebuils, at which point you may be able to replace the assembly and fit one that houses the much larger bearing finally used in the later 997.1 which is pretty much bombproof.

Anything else is snake oil and no better than what you already have.

You've more chance of getting Coronavirus than a perfectly good dual row with the seal flipped off failing.
 
I had my engine out, we changed a fair number of things including the clutch, I did exactly what Mark (and many others on here) did.

I'd also advise a bit of caution with some of these aftermarket IMSB fixes- at least one of them feeds unfiltered, pressurised oil into the bearing straight from the sump, which I'd consider unwise.
 
Answer A

If you're really concerned buy a magnetic sump plug. Perform interim oil changes every 6 months and check the internal oil filter.

Just enjoy the 911 and drive it.
 
A!
Now stop worrying and drive that car as it was intended, you must have one of the most sorted 996's out there, enjoy it.
 
Easy answer... stop worrying and drive it. It's had the best treatment already.

Lovely car that, relax and enjoy :thumb:
 
Here's a bit of real world experience..

My colleague at work has a 1998 dual row car with 152k miles on it on the original bearing and it's running fine and it's never had a speck of metal in the oil, it runs like a dream and pulls like a friggin horse.

I have a 1999 dual row car with 82k miles on it, my IMS nearly failed at 78k miles and swapped before any serious damage was incurred.

I caught my failure by simply dropping the oil filter (you can do this without changing the oil, there's absolutely no need to dump £90 worth of oil out of your car) you will loose the amount in the filter housing only, you will need to top this up with fresh oil and put a new filter in. You can check this as often as you like and you need nothing more than a shallow oil pan, some rubber gloves and a oil filter wrench and the ability to lay on the ground, you don't even need to jack the car up to do this.

If your filter is clear, then your IMS is fine, if it's full of sparkly stuff then cease using it and get the bearing changed.

It's not a hard thing to monitor, but I'd still advise you get it changed because I genuinely believe they will all start to degrade eventually, wheel bearings don't last forever so why should an IMS bearing? (And yes IMS bearings are subject to some pretty extreme loads just like wheel bearings too).
 
Hi all
Thanks so much for your response so far. Most helpful and much the same as the UK Facebook page!

I guess a magnetic sump plug would at least give me some means of monitoring so will probably go that way.

I guess the only concern are stories such as DarthFaker's.
It's not really a money thing. I'd happily invest if it was widely believed this was a solution but the reports are so contradictory.
IE
a) lots of info only saying to remove a good bearing and replace can do more harm than good.
b) nothing really concrete to say that the 'upgrades" are 100% suitable risk free alternatives.

As this was checked not long ago (and confirmed ok) and from what I've read I'm tempted just to fit a magnetic sump plug and monitor.
The car will only do circa 3k PA max anyway so I'm guessing annual checks to that sump plug should be ok.
Then if anything is ever found, I'd change at that point ?
:dont know:

This is a minefield really isn't it, but really appreciate everyone's input.

PS, realise there is no real sulution to this problem. It's just a case of picking the option that sits best with me and having a bit of faith I guess.

Keep the comments coming folks :thumbs: :worship:
 
You can quickly make yourself crazy over this stuff; there is so little empirical data and so much FUD that it's almost impossible to know the true situation. My personal opinion is that most IMS that were substandard have already given up by now, but the age of the cars now is that preventative maintenance is not a bad idea.

In that vein I have just had the clutch replaced on my high-miler C4 and Northway recommended I take the EPS IMS solution at the same time. As I trust the guys there to know their stuff, that's exactly what I did. Was it absolutely necessary? Probably not. Was I awake at night worrying about my IMS? Definitely not. Do I feel better for having it done? Possibly, but only a little bit.
 
I have the EPS without the oiling modification, as they said it can run fine either way and I'm certain that running unfiltered oil through the IMS tube via the oil pump woodruff key isn't the best idea, we all know splash lubrication is fine for an open unsealed IMS bearing anyway.
 
Quote from the EPS website to back up above post...

' Is the Pressurized Oil Feed Kit necessary?

No. The bearing is completely submerged in oil thus not requiring the Pressurized Oil Feed Kit. However, due to some misleading information of the internet, some installers feel that it's important to implement this modification. '

I also thought that this comment was interesting...

' Unlike ANY other cylindrical bearing solution, our axis load (thrust control) is not applied to the rollers, instead, it is applied to the entire perimeter of the outer race. The main advantage of this technology is that the rollers are not loaded from the side. '
 

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