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YOUR RESEARCHIMS bearing?
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Install on the car
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Performed · outcome unconfirmed · Original poster
The sealed bearing in the pictures is a 5204 2rs which I acquired for measurement purposes; it will not be installed on the car.
Leading evidence: 'Install on the car' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Clean just one or two specks of metal' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
Organizing all of the tools necessary to inspect the ceramic hybrid bearing that was installed on the car at 60k miles or so.
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Performed · outcome unconfirmed · Original poster
The original bearing was replaced proactively when I serviced the clutch at about 2 or so years ago, it was in great shape (no axial or radial play).
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Performed · outcome unconfirmed · Original poster
It was replaced proactively (the engine was healthy) when the clutch assembly required service (throw-out bearing was damaged/worn).
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Suggestion · Original poster
The oil sump looks clean, just one or two specks of metal.
Clean sump, pickup screen and in sump aos, i noticed
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Suggestion · Original poster
When cleaning the sump, pickup screen and in sump AOS, I noticed that the IMS bearing seems to be almost fully submerged in oil when the dipstick is at the full mark.
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I replace and dissect the filter every 2.5k, with a 5k OCI. I use a 50/50 mixture of M1 0w-40 and M1 10w-40 in the winter and a 50/50 mixture of M1 0w-40 and M1 5w-50 in the summer. Oil pressure is very good. The car has accumulated 95k miles. The engine started to idle strangely about 3k ago. These are some photos of the last filter. I don't have any photos of the magnetic drain plug, but it did have a fair amount of metal shavings on it. Sorry about the low quality photos.
Are those particles on the outside of the filter elements?
I just changed the filter tonight as part of the half-season change over, and was wondering if the oil flow is from the outside of the filter element to the inside, which seems to make more sense.
Debris can easily bypass the filter at start up when pressure is extremely high. This is the time when debris damages the engine as it bypasses the filter in the bypass oil laden with it.
The "finger test" in the center of the oil delivery port will tell you if the main and rod bearings have been fed with debris laden oil. This is why we have a severe dislike for the factory oil filter housing.
If the oil bypass valve open due to high pressure, wouldn't the oil be diverted back into the sump?
I have the SPOFA and use Mobil 1 M1-107 oil filter or K&N equivalent along with a lower temperature thermostat. The SPOFA has reduced the start-up noise considerably, I'm guessing because of the anti-drain back valve. I haven't driven the car (except for re positioning it in the garage) after the last OCI. Bad timing to switch to Redline oil. OUCH!
Who knows? But it does result in a "blend" of oil that contains 50% of an oil not suitable for use in these engines.
10w-40 is not an approved viscosity of oil for these engines. Why anyone would want to dilute an approved oil with with an unapproved oil is beyond me.
If 0w-40 is not to your liking due to the only thing that makes any sense would be the ambient temperatures in your region then there is 5w-40, even a 5w-50 (not a typo for 15w-50!).
Even blending say 0w-40 and 5w-50 to get God only knows what is not recommended. The additive packages even the base oil blend is not likely the same so you have some hybrid oil, Frankenstein oil, for who knows for what purpose and suitable for who knows what but not for your Porsche engine.
Are you sure that stuff is ferrous? I get some bits like that but they are non-ferrous and I think it's just flashing from machining/casting in the aluminum parts of the motor.
If accountants hasn't engineered the engine the bypass oil would divert back to the sump.
Familiarize yourself with the oil system of the engine and you will see that bypass oil is unfiltered oil. Further, this bypass oil is from the bottom of the filter housing and guess where all the debris collects? You got it.
Yes, unfortunately it is ferrous, I just ran a magnet over it and all of the shavings was attached to the magnet.
It seems that #4 is the high pressure oil relief valve, which diverts the oil back into the sump. Or am I missing something?
This system layout is very confusing.
Do not confuse the oil pressure relief valve located in the oil pump housing with the oil filter bypass valve located within the oil filter canister.
The car is up in the air. The oil sump looks clean, just one or two specks of metal. There is no debris in the filter with just about 5 minute of engine run time.
Next course of action is to drop the transmission and inspect the IMS bearing.
Organizing all of the tools necessary to inspect the ceramic hybrid bearing that was installed on the car at 60k miles or so. The original bearing was replaced proactively when I serviced the clutch at about 2 or so years ago, it was in great shape (no axial or radial play). The sealed bearing in the pictures is a 5204 2rs which I acquired for measurement purposes; it will not be installed on the car.
[QUOTE][Are you planning to re imstall the hybrid?/QUOTE]
Once a bearing is removed using this extraction method, it should never be reused. During the extraction process, force is applied axially to the inner race and transferred through the ceramic ***** to the outer race. The contact points between the ***** and the inner and outer race will deform ever so slightly.
If the bearing is damaged or worn, I'll replace it with a sealed ceramic hybrid.
I disagree. If the clutch wasn't slipping then keep the set together until it's time to change it. I've seen and had flywheels that lookedlike this and yet worked perfectly fine.
Hi DC, will be interesting to see what you find.
BTW, what is the brand/make of the tranny lift you have?
They are hard to get here in Australia and I am lookin' to buy one from the USA and it is good to see what others use and are happy with before I get one sent downunder
Thanks
DCQT,
Have you thought about adding one of these to your assembly?
http://tunersmotorsports.com/?page_id=103
Creator of the DOI gets involved with the discussion here.
http://forums.pelicanparts.com/boxst...injection.html
That assembly will provide more than enough lubrication and prevent debris from entering into the bearing when the engine is running.
Here's my take on the IMS bearing design.
It is possible that an entire team of Stuttgart finest powertrain engineers (along with their vendor's/supplier's engineers) over looked the simple fact that the IMS bearing was not designed to operate in this environment (the seals will allow oil intrusion over 240f and the races and ***** will expand and internal clearances will be reduced over 250f). A simple viton seal would have solved the oil intrusion problem.
It is more probable that the original design specified a sealed ceramic hybrid bearing with a seal that will provide for oil intrusion (hence their original recommendations for 0w-40 oils); somehow during the final product cost analysis a decision was made to source a lower cost alternative.
Hence my decision to go with a sealed ceramic hybrid bearing.
Imre, my thinking is that you have the trans out anyway. The car is older, why not replace it while your that far into it?
To the OP, was this CH bearing installed in a marginal or healthy engine at the time? Cant expect even a CH bearing to survive if the engine was already contaminated by a IMSB failure. I know you said the original was OK and the LNE CH only has 60K miles on it but I think even LNE calls it a service item now. The LNE is just a CH version of the original, nothing special. If you put 60K miles on the LNE bearing, youve already exceeded their recommended replacement mileage.
I would think anyone with a M96 better just be prepared to at least inspect and/or R&R the IMSB every 30K to 50K miles unless there is something obvious indicated sooner. If you cant handle that, youve bought the wrong car. I suppose an owner could just drive in ignorant bliss and risk failure if they can afford a $20K engine for a $15K to $25K car.
It was replaced proactively (the engine was healthy) when the clutch assembly required service (throw-out bearing was damaged/worn). The original bearing which accumulated 60k miles on it was like new when removed, no significant axial or radial play (it was and still is very tight). The LNE ceramic hybrid bearing has accumulated 35k miles or so.
I have owned this car for over 12 years.
Given the number of 200k plus mile Boxsters out there on original bearings the above statements are ... inoperative to say the least
Now that it's becoming more and more obvious that the insertion of hybrid bearings (or other "solutions") is blowing cars up right and left there is little remaining doubt about the efficacy of these "fixes." Banging on the intermediate shaft is NEVER a good idea. The journal tolerances are measured to the thousandths of an inch at the factory. It's all but guaranteed that insertion of a replacement bearing will take the shaft out of factory spec. From there it's a crap shoot how long it goes. I would never even consider purchasing a car with an after-market bearing in it. Every single one of them is a time bomb.
You seem to know quite a bit about this subject. What is the actual MTBF of the factory IMS bearing? Same question for the aftermarket kit bearings. Can you share the study / report / findings?
You have a SR bearing so I assume thats the one you want to know about? I dont know squat about the DR but I know all the specs on the OEM SR if thats what your asking. Ditto on the LNE SR too. I researched the $%^& out of the SR bearing before I decided what to use.
The OEM Porsche single row bearing is an off the shelf crappy $12 bearing. I can prove it if you care to believe the facts. It has seals that were meant to keep out dust and dirt not hot motor oil. Why do I feel like this is a repeat?
Finally had some time to inspect the flange and dissect the bearing. There is considerable spalling on the inner ring outer raceway (just half of the raceway), about 120-135 degrees. There is also some wear on the outer ring outer raceway. There is no wear at all on the inner raceway.
Good, you can re-use the *****... ha.
So the ***** were fine but the races were galled/damaged (Rockwell hardness of silicon carbide ***** is higher than race steel). It sounds in your story like there was no debris from previous bearing present to enter the open ended bearing, so what could have done this? Maybe the races were defective? Where are all the ball bearing armchair experts when you need em?
Been there.
The IMS flange bore and or the crankshaft carrier were mis-machined, thus overloading only one portion of the inner race. No way to solve this one without extensive machining requiring complete engine disassembly. This machining issue is one cause of IMSB failures that most haven't considered or experienced.
Sooooo...........
1.- Is it fare to say that many of the previous failures (factory bearing) could have been caused due to the flange or crankshaft carrier and not the original bearing ????
or
2.- How can we explain the original bearing was in "like new" condition (when removed) ???
(The original bearing which accumulated 60k miles on it was like new when removed, no significant axial or radial play (it was and still is very tight).
3.- Given the above, Could it be that the actual LN bearing was defective or installed incorrectly ???
Just asking.........
When cleaning the sump, pickup screen and in sump AOS, I noticed that the IMS bearing seems to be almost fully submerged in oil when the dipstick is at the full mark. This would explain why a large portion of perfectly fine IMS bearings are flooded with oil when removed. Has anyone removed a non-damaged IMS bearing that did not contain a good amount of oil in it?
All along I've been scratching my head thinking there must be a tolerance variability issue at play here. Because if it were
only
a design defect, like the bearing being sealed, or a too-low-load-rating, then the failure % and survival % should almost be reversed from what they are.
The 5204 2rs bearing is 20.6 mm in width, while the LNE CH bearing is 20.2 mm wide; I decided to take the LNE IMS flange to a friend's shop to get the shoulder turned down .40 mm on his lathe. I was also able to locate a Smalley DNH-47 retaining ring that when cut in half fit the groove perfectly at .845 mm. A sealed 5204 2rs CH bearing from Boca Bearing was installed.
Installing this bearing sealed is a bad idea. Those seals are meant to keep out dust and dirt, not engine oil. I would want the oil to be allowed in and through the bearing. Guess you didnt see my thread explaining this.
It should look like the one in pic 1 so you dont end up with pic 2:
I think the seals was designed to allow for oil penetration, the grease in the bearing will provide lubrication until the seals wear. The LNE CH bearing that was removed from my car show damages that are consistent with debris contamination, the debris could have came from any of the wear components in the engine. Once bruises and stress risers are create it does not take long for spalling to occur. It seems that the oil level when full is about 3/4 way up the IMS bearing when the engine is not running. If that is the case, an open bearing will act as a pump and any debris within the vicinity will be sucked in ( think water wheel). This would explain why the damage to my bearing was on only half of the exterior raceway; the contamination occurred when the engine was running.
I had mine in there with the seals and ~300ml of engine oil in the tube, for over 10K kms. I'm glad I kept the seals as there was lot of aluminium in the first oil change after the engine was put back together. Without seals, all that would have gone through the bearing.
So you really believe that seriously contaminated splash oil is only going to affect the IMSB and no other components? This theory would require that the contamination originated in the sump and was confined to the sump which is highly unlikely.
Yes, the engine is running perfectly with about 2K miles since the repair.
In my situation, I believe the contamination was contained within the sump due to the LNE SPOF adapter that was installed.
Some thoughts on the IMS bearing lubrication and seal.
As the engine is warmed up during operation the air in the IMS tube will expand and escape between the seals and the bearing inner ring. When the engine is shut off and the oil level begins to rise above the inner ring, oil will be drawn in by vacuum as the air in the tube cools down. Oil is constantly being drawn in and expelled through the IMS bearing and therefor the tube at every cycle. The outer seal will act as a filter and prevent any debris from being drawn into the bearing.
Ceramic ***** are harder (less likely to deform), lighter, smoother (so they have a lower coefficient of friction than metal *****), and demonstrate less thermal expansion than metal *****. They are generally more uniform in size, reducing the chance of uneven loading. Hybrid ceramic bearings require less lubrication than a standard bearing - I imagine that this is the single most important factor when electing to go with a hybrid bearing for our specific application.
Not 100% certain, however I thought the Jake Raby IMSB was ceramic hybrid, and the ceramic is just the coating on steel *****, and the ceramic surface was more tolerant to less lubrication under the right (wrong!) conditions which would kill the steel *****.
x3. I was adding that sentence to my post.
Since lubrication seems to be provided by splash oil, using a bearing that requires less lubrication seems like a great choice.
No worries.
Although the first 3 hits when I searched for ceramic hybrid bearings all indicated the ***** are silica nitride and 40% lighter than steel, ie. I think these are entirely ceramic rather than just ceramic coating, not sure if the LN IMSB is the same or different.
From LN Engineering: "The ceramic hybrid bearing used is designed to function on splash lubrication from engine oil alone, but is submerged in oil as well, depending on operating conditions due to its location in the engine’s “integrated dry sump.”"
My understanding based on stuff read here and elsewhere is that keeping the oil level at the highest point of the "normal" range ensures that there is oil in the shaft. This is offered with my standard disclaimer: I'm an idiot.
Thanks Jake for the clarification, wasn't sure initially, but had the feeling when other "ceramic hybrid" bearing suppliers all indicated solid silica/silicon nitride, else it would be hard to achieve 40% weight reduction!
I'm just glad I've got one in my 99 C2!
Side question Jake, I'm getting ready to install the sump spacer kit and I noticed in your video that you spread the loctite sealant over the mating surface completely in a thin film versus squeezing a small bead out which it seems I see being done most of the time by others. Is this a function of using the loctite vs the Porsche oem material or is that just your personal application preference?
thanks
rich
Our preference comes from seeing more failed engines than anyone in the world, and then resurrecting those.
We avoid this blocked oil pick up by utilizing the proper sealant, applied in our own manner and in the correct quantities, on the proper surfaces.
Avoiding the blocked pick up tube avoids this (pics all from the same engine that died after death was induced by sealant and a negligent technician who applied them):
And then ultimately this happens�
Then your pistons turn into this..
And your rods do this�
See how the dynamics of this failure unfold in this album. We saw this one 4 times this year and in every case it cost 24K to overcome it.
https://www.facebook.com/media/set/?...4914693&type=3
The work was done by a Porsche only shop thats well known. They had just carried out sump replacement a couple of weeks prior to the engine failure that occurred.
Ok but that's not whatnI was refering to. Once the con rod bearing spum and the engine started to sound like a diesel, why didn't the owner shut it town. Looks like it was driven until it threw a rod and then some. That's why I said the owner must have been deaf not to hear anything.
It came apart at speed. By the time it made any noise the factory rod bolts had already failed and the rod was expelled. Thats the issue with stock rod bolts, they have no margin of error.
