Opinions are welcome on IMS issue. ...I know

[stelan]

Oem IMS bearings are very close in design to wheel bearings, they are permanently greased and have seals to prevent grease from going out, dirt from going in and oil from washing the grease out, when seals fail bearing will fail, think of a wheel bearing without the seals, it will fail quickly, It has been discussed a lot if the ones that actually failed it was due to bad oil that affects the seals or extreme pressure/ vaccum in cranckcase or just a bad batch, I would say if you are not replacing it do frequent oil changes, make sure you have a working AOS and drive it often.

[JFP in PA]

Originally Posted by stelan

Oem IMS bearings are very close in design to wheel bearings, they are permanently greased and have seals to prevent grease from going out, dirt from going in and oil from washing the grease out, when seals fail bearing will fail, think of a wheel bearing without the seals, it will fail quickly, It has been discussed a lot if the ones that actually failed it was due to bad oil that affects the seals or extreme pressure/ vaccum in cranckcase or just a bad batch, I would say if you are not replacing it do frequent oil changes, make sure you have a working AOS and drive it often.

From experience, I really do not think that the AOS condition has much to do with oil intrusion of the OEM IMS bearing. For the most part, the seals just harden over time, and with the bearing partially submerged in oil, and the shaft itself cooling and pulling a very slight vacuum on the IMS bearing as the engine cools after shut off, slowly washing the grease into the shaft and out of the bearings. This is the reason that the every shaft we have ever seen during a retrofit is at least partially flooded with oil.

[Jamesp]

Originally Posted by JFP in PA

F...with the bearing partially submerged in oil, and the shaft itself cooling and pulling a very slight vacuum on the IMS bearing as the engine cools after shut off, slowly washing the grease into the shaft and out of the bearings. This is the reason that the every shaft we have ever seen during a retrofit is at least partially flooded with oil.

+1. The real design flaw.

[10/10ths]

....just change the damn thing.

If you want a 986, just know that you will replace the IMS. Period. Just add $2,000 to the sticker price. Done.

Easy.

Change.

The.

IMS.

Just do it and start enjoying life.

Now I'm done. Gotta drive.

[Dave S.]

I used to worry about the IMSB failing. Replaced the IMSB, clutch and RMS in my '03 at 25k miles for $2100, and now I don't ever think about it. The ceramic bearing is good for 50k miles and the clutch should easily last that long so it will have to be done again at 75k miles.

I found a local independent shop that had done a bunch of them. They showed me boxes of failed parts from ones that didn't get it done and few near failures that they replaced just in time.

It's a real issue and if it bothers you, get it done and never worry about it again. I'm glad I did.

[mikefocke]

What pray tell did the "near failures" look like. I've always heard that once the metal starts falking, it goes everywhere including very narrow oil passages and some inventors of these things won't install any IMS in such an engine. So I'm interested in how they determined it was "near failure" but OK to install a new bearing.

[Dave S.]

Originally Posted by mikefocke

What pray tell did the "near failures" look like. I've always heard that once the metal starts falking, it goes everywhere including very narrow oil passages and some inventors of these things won't install any IMS in such an engine. So I'm interested in how they determined it was "near failure" but OK to install a new bearing.

Mostly rubber seals on the bearing failing. Oil intrusion, no grease left in them.