IMS center bolt

[Homeoboxter]

Mine had an M8 1.0 mm center bolt, it`s a 1999 Boxster. I wouldn`t waste an original dual row bearing at such a low mileage though by pulling it out. Just a thought.

[WhiteyII]

Thanks appreciate the quick response. I’m changing it with low miles mostly due to the clutch..... which leads to the RMS. Which leads to the IMS. I would prefer to remove the inner seal on the IMS bearing but there’s no way to remove without pulling on the inner race which is fine to get it out but not to reuse. Too much stress/damage unseen to comfortably trust it after that. I see videos of guys “tapping” on the inner race driving it in that last 16th inch possibly damaging the bearing. This is done on the way out. I went back and forth on leaving it completely can’t go that either.......

[elgyqc]

Originally Posted by WhiteyII

... I would prefer to remove the inner seal on the IMS bearing but there’s no way to remove without pulling on the inner race which is fine to get it out but not to reuse. Too much stress/damage unseen to comfortably trust it after that. I see videos of guys “tapping” on the inner race driving it in that last 16th inch possibly damaging the bearing. This is done on the way out. I went back and forth on leaving it completely can’t go that either.......

Why remove the inner seal? I removed the outer seal to allow engine oil lubrication and other than that left the original bearing as it was. The car has been running for 2 years since with no problems.

[Homeoboxter]

Originally Posted by elgyqc

Why remove the inner seal? I removed the outer seal to allow engine oil lubrication and other than that left the original bearing as it was. The car has been running for 2 years since with no problems.

I agree. Removing the inner seal wouldn`t make any further difference.

[piper6909]

Originally Posted by elgyqc

Why remove the inner seal? I removed the outer seal to allow engine oil lubrication and other than that left the original bearing as it was. The car has been running for 2 years since with no problems.

Wouldn't the oil flow from the inside outward? Keeping the inner seal in blocks the oil flow. Maybe not completely, but it surely restricts it.

[elgyqc]

Originally Posted by piper6909

Wouldn't the oil flow from the inside outward? Keeping the inner seal in blocks the oil flow. Maybe not completely, but it surely restricts it.

The inner seal side of the bearing is in the IM shaft, so the only oil on that side is oil that has passed through the bearing and is trapped in the shaft. The good stuff is on the outside.
The PCA videos with Jake Raby explain in detail what is happening with the IMSB.

[WhiteyII]

So a couple questions, the really crappy oil that comes out when the bearing is pulled is there because of the inner seal causing stagnation or in other words because the inner seal doesn’t allow the oil to flow thru the bearing? Does the Retrofit LN bearing have an inner seal or does it let the oil flow thru or rely on immersion and splash?
I appreciate you guys and your knowledge.........

[Homeoboxter]

Originally Posted by WhiteyII

So a couple questions, the really crappy oil that comes out when the bearing is pulled is there because of the inner seal causing stagnation or in other words because the inner seal doesn’t allow the oil to flow thru the bearing? Does the Retrofit LN bearing have an inner seal or does it let the oil flow thru or rely on immersion and splash?
I appreciate you guys and your knowledge.........

The original bearing is sealed with grease filled inside. IMS is a tube with about a liter of air trapped inside, since both ends are closed. When the engine warms up, pressure rises within IMS, and after a while air will leak through the bearing`s seals, creating vacuum when the engine cools down and the pressure drops. Eventually this will cause the oil to seep into the IMS, and will fill it, since the entire shaft is submerged in oil. Since it does not circulate so well, and you can`t drain it when replacing engine oil, it will become darker and crappy than the rest of the oil in your engine. So, if you just remove the outer seal, the bearing will get sufficient lubrication from outside. Somewhat depending on the oil level in your crankcase, it will get direct oil from being submerged, from splash, plus oil mist.

As far as I know the retrofit has no seals.