Ims Bearing Fix

[rabkay]

i would like to get some clarification on the "ims" issue.

first: we are aware there a percentage of 996/997 engines grenade due to ims. we have no real data as to the frequency -only an anecdotal percentage of perhaps 3-5% -never confirmed by porsche.

second: ln engineering has created an elegant replacement bearing for the intermediate shaft. is it a must do?

now the hard stuff. will this replacement if done in a preventive manner remove all of the ims issues from our cars?

i know this is a new item and we are unaware of its own longevity - aside from that is original bearing failure the only or the most common cause of ims?

i appreciate you input to try an get a better understanding of if it makes sense to do this "upgrade" .

thanks,

larry

[1schoir]

i would like to get some clarification on the "ims" issue.

first: we are aware there a percentage of 996/997 engines grenade due to ims. we have no real data as to the frequency -only an anecdotal percentage of perhaps 3-5% -never confirmed by porsche.

second: ln engineering has created an elegant replacement bearing for the intermediate shaft. is it a must do?

now the hard stuff. will this replacement if done in a preventive manner remove all of the ims issues from our cars?

i know this is a new item and we are unaware of its own longevity - aside from that is original bearing failure the only or the most common cause of ims?

i appreciate you input to try an get a better understanding of if it makes sense to do this "upgrade" .

thanks,

larry

Whether this is a "must do" or not has been, and will continue to be , a topic of much debate. I guess it depends on your particular tolerance for risk. If you can "handle" the actual event and have a plan as to what you would do if it happens you are less likely to do it as a preventive measure.

The longevity issue will only be answered with the passage of time and the number of miles that people who have done the upgrade achieve without the IMS failure. As far as whether this is a "permanent" fix or not, I am informed by the fact that LN Engineering has recently added language on its website that suggests inspection of the replacement bearing on a schedule. They seem to have abandoned their original position of "replace it with one of our bulletproof bearings and forget it". The parts that fail or that are a known weak point are the bearing itself, the fact that the bearing is sealed (thereby preventing lubrication by engine oil if the grease inside the seal bearing washes out) and the size/diameter of the flange bolt.

Then there is the issue of whether all of the reported IMS failures are really IMS failures or one of the X number of modes of failure that Jake Raby has documented.

Regards, Maurice.

[rb101]

I replaced my IMS bearing with the LN upgrade at 105K. Only time will tell if it fixes that cause of the engine failure. My opinion I would do the bearing upgrade with other service that requires removal of the transmission (clutch/RMS/IMS seal/AOS). The other worthwhile maintenance is replacing the cam chain guides and chain adjusters. Mine were badly worn and scored at 105K. The new adjusters reduced the startup chain noise.

[Stefan]

The "upgrade" is a waste of money. It is not proven and it is not guaranteed. If you're really worried, ask your insurance company if they will write up a policy just for IMS failure and it will cost less and it will give you peace of mind.

[Dharn55]

Not sure I would agree with Stefan. The IMS is the most common cause of catastrophic failure in the M96/M97 engines. There is a interesting article on this in the latest issue of Excellence magazine. It discusses the design and issues of the IMS and notes IMS failures as the most common issue. Next month they are going to do an article on the upgrade.

But the factory bearing design is pretty poor, and the LN replacement is a much higher quality part. I have had my trans off and inspected the OEM bearing, it was not loose so I removed the outer seal and left it in. I choose to do this as I was fixing a cracked head and was not sure if that repair would work. 3,000+ miles later it is running fine. I can only tell you that next time I have my trans out I am going to do the LN upgrade.

The factory bearing is "proven" to fail and is not guaranteed either (beyond the base warranty).

[jay abrams]

Asking your insurance company about an IMS Bearing rider is an interesting concept. Traditional insurers may balk at it (they will more likely than not have no clue of what you are asking), however, a collector car insurer may take you up on it. I'll give mine a call Monday.

Jay

[PILFILR]

My Porsche dealer spent 30 minutes on the phone talking me out of the upgrade. They are aware of the "fix", but worry about doing other damage while pulling the bearing. Also, in my case, I have a Tiptronic tranny. Acording to my dealer...There have been far fewer failures with the Tiptronic. They suspect there is less vibration in the drive train over a manual tranny. Any IMS failures here on the forum with a Tiptronic tranny??

I decided to put it on hold...they quoted me 20+ hours labor to pull and replace the tranny alone. Is this correct?

[txhokie4life]

My Porsche dealer spent 30 minutes on the phone talking me out of the upgrade. They are aware of the "fix", but worry about doing other damage while pulling the bearing. Also, in my case, I have a Tiptronic tranny. Acording to my dealer...There have been far fewer failures with the Tiptronic. They suspect there is less vibration in the drive train over a manual tranny. Any IMS failures here on the forum with a Tiptronic tranny??

I decided to put it on hold...they quoted me 20+ hours labor to pull and replace the tranny alone. Is this correct?

Yes -- I bought and replaced an IMS failure on a '99 Boxster Tip

Mike

[greerj1]

Gentlemen:

I had noticed a vibration at 3,000 rpm last fall om my 01 996 w/94,000 miles. It had came out of the blue. I thought it could be the tranny mount which was cracked. I removed the tranny, clutch and flywheel to have a look at the IMS bearing and seal. I removed the IMS support and noted a large amount of axial and radial play in the bearing. Axially (in and out along the center line) there was at least 3/16 of an inch of play and radially there was about 1/16. Both bearing seals were in place, when I tore down the bearing, the balls were severely pitted and the races worn. This was about to fail and would have been catastrophic to say the least. I had my indie put in the bearing upgrade in and it has only been about 500 miles since, the vibration is gone. So the car is back up on blocks now, but for the RoW M030 suspension upgrade and brake job. It just keeps getting better.

In closing, at least have a look at the bearing. I got lucky with some symptoms, alot of people do not.

James Greer

[whall]

"I decided to put it on hold...they quoted me 20+ hours labor to pull and replace the tranny alone. Is this correct?"

I was charged for 8.4 hours of labor by my dealer to replace clutch, RMS and IMS bolts. 20+ hours to pull and replace transmission seems to be guilding the lilly....or, making up for lost time on another customer's job.

Bill

[PILFILR]

My Porsche dealer spent 30 minutes on the phone talking me out of the upgrade. They are aware of the "fix", but worry about doing other damage while pulling the bearing. Also, in my case, I have a Tiptronic tranny. Acording to my dealer...There have been far fewer failures with the Tiptronic. They suspect there is less vibration in the drive train over a manual tranny. Any IMS failures here on the forum with a Tiptronic tranny??

I decided to put it on hold...they quoted me 20+ hours labor to pull and replace the tranny alone. Is this correct?

Yes -- I bought and replaced an IMS failure on a '99 Boxster Tip

Mike

Mike, What was the labor time to do this??

[logray]

I've been chasing down engine vibration in my99 manual 996 for some time now. It's at 70k miles. The vibration is noticable mainly at idle, but I've also noticed some around 70mph which I can attribute to a need for some new rear tires. Other than the vibration the car is running great. Usually when I have it topped off with oil it is slightly less apparent, but still there.

I've replaced the engine motor mounts which helped the vibration some and was under the car today to inspect the tranny mount. It is definately shot. With a jack supporting the transmission, and the bolts from the mount removed - I could easily see the mount is worn and not supporting as originally intended. There is a lot of play in the mount and the center part is easy to move around so I'm guessing it's shot, also see a few cracks near the top of the rubber.

I'm contemplating dropping the trans to have a new mount pressed in. Also reading about filling the gaps in the mount with windshield sealant, although I'm guessing that is going to make the ride stiffer (of course how much stiffer could it get with PSS10's ??? )

NOW I stumbled on this thread about IMS failure and excess play in worn bearings causing vibrations. While I'm in there would it be advantageous of me to replace the IMS bearing? Chain, guides, adjusters, etc.?

Does anyone have a good way to tell if the vibrations I'm seeing and feeling from the engine are caused by play somewhere there shouldn't be?

I have a PST2 and Durametric... already looked at camshaft deviation which reads 0 degrees? No fault codes. Not sure where else to look.

The crankshaft pulley is noticably wobbling a tiny little bit which worries me.

I had a shop do a new clutch and flywheel resurfaced, also a new RMS about 35k miles ago. Oh and I recently swapped the spark plugs and did a compression test which showed all cylinders were in spec... but problem was there previous to this.

Edited May 12, 2010 by logray

[Wayne R. Dempsey]

It's definitely an issue to be concerned about. I've designed an IMS replacement kit that will be out very soon - we're testing it right now. There's a big thread over on the Pelican Boxster forum right now regarding our new kit and how it compares to the LN Engineering kit...

-Wayne

[logray]

Interesting Wayne. A pelican "branded" replacement, sourced from ln engineering and marked up 100% I presume? j/k! LOL. (all in jest as I love pelican and certainly have spent many paycheck there... tell us more!)

I'm not ruling out IMS as a possible fix for the vibration but have to also consider a possible misfire problem, flywheel, or just normal 996 passenger seat shaking at idle... and I'm reading too much into the hype.

Edited May 12, 2010 by logray

[txhokie4life]

My Porsche dealer spent 30 minutes on the phone talking me out of the upgrade. They are aware of the "fix", but worry about doing other damage while pulling the bearing. Also, in my case, I have a Tiptronic tranny. Acording to my dealer...There have been far fewer failures with the Tiptronic. They suspect there is less vibration in the drive train over a manual tranny. Any IMS failures here on the forum with a Tiptronic tranny??

I decided to put it on hold...they quoted me 20+ hours labor to pull and replace the tranny alone. Is this correct?

Yes -- I bought and replaced an IMS failure on a '99 Boxster Tip

Mike

Mike, What was the labor time to do this??

IMSR -- about 2 hours.

To do the whole project engine pull and replacement plus all the replacement parts I put in the engine

(coils,plugs,tubes,h20pump,low temp thermo, aos) -- I never counted the time.

Mike