IMS Center Pin Re-seat on Reman motor

Pulled the motor on my 01 C2 to address VarioCam chain guides and general maintenance. While at it, figured I would pull and inspect or replace the IMS. Turns out the IMS cannot be removed without cracking the block open. Why.... I have a reman engine that was put in under warranty by previous owner in 2008. Seems Porsche modified the IMS shaft and there is no longer a visible outer flange by which to brace the removal tool to. That, and the bearing is physically too big to fit through the case opening. In all my research, I completely missed this knowledge nugget. Oh well. Prior to learning this, I tapped the threaded center pin back into the IMS shaft. So, now I need to pull it back through and seat it in order to set the cap back in place. Should be as simple as finding an M8 coupler and threaded rod slid through a large enough socket to brace against the inner race of the bearing. But, in an effort to not learn the hard way, thought I would ask the book of knowledge first. Thanks in advance.

You will likely damage the bearing bracing on the inner race.

Wow! Wow!! There is just so much wrong with this. Here's hoping there is someone somewhere out there with knowledge and experience that can help you back out of what you have done. You are in way over your head. Think $20-25K in repairs with having to split the engine case.........

The prospects are going to be challenging. Do you have the engine out already, or did you just drop the transmission? The good news is that you will be an expert at this engine when you are finished. I wish you the very best,

How much force was exerted driving the center stud to that position?Because if it was a lot you are putting force on the bearing ***** and races. My personal experience with my �large� bearing is my center �studs� interference fit is not that much.You could try your method and pull stud back thru against inner race,and then rotate by hand and see how bearing feels.Worth a shot......If you are going to give it a go and button it back up,it is recommended to remove outer seal in bearing,before putting back together. good luck.

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This is 100% true for every single M96/7 engine. All of them. Inner or outer? The shaft needs to be pulled back though the inner race. I would argue that if he is able to get a grip on the threaded shaft, he should pull it back through while bracing against the inner race. Bracing on the outer race stresses the bearing...which unfortunately is what he did when he drove the shaft into its current position.

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No, no! On the contrary, he needs to pull against the inner race to get the centre stud/support back in place. If you can get the centre stud back in the hole then it will be a relatively simple procedure but some tools will need to be made to make the rest of the pulling possible. All is not lost.

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This is correct.

Yeah, I meant he’s still likely to damage it. Bracing against the inner is much better than the outer, but I’d still worry about the bearing being damaged. It likely was damaged when the center was pushed in. Why was it pushed it is my first question. Obviously not using LN IMS Bearing removal tool.

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I have a feeling if he did have the LN IMS bearing removal tool, he would have tried to pull the bearing out! He is obviously in way over his head. If he had checked the bearing cover flange first, that would have told him what bearing he has. And checked the engine number for AT. I feel sorry for the OP because where he is right now he most likely has already damaged the bearing races.

The best way I can think of is go in through the oil pump side , tap a small hole in the cap in the end of the ims shaft so you can insert a long thin rod through the ims shaft to push the centre pin back through , of you can get enough back so you can then re mount the ims flange to support the centre race while you use the nit to thread onto the centre bolt and draw it through by tightening up, the flange will support the centre race this way of the forces as you tighten the centre stud , I punched a hole in my ims shaft to install my pea oil feed , so after maybe you could install this aswel ? There is another member who uses a punched hole for inspection with 6mm fibre optic camera so you could get a long 6mm rod , should be strong enough for the job , maybe a welding rod or something similar , best I can think of ?

The first picture is a dead straight on,he still has access to threads.

The 6305 bearing is compromised and I would NOT risk a $25K engine by just "tapping" the center stud back into position. IMHO, this engine block needs to be split, bearing removed and a new bearing CORRECTLY installed into the shaft.

A deep groove ball bearing can take an axial load .25-.5 times its static radial load rating depending on size. I don't know how much force is needed to push that center pin in, but I'm just sharing as food for thought. OP, I also have a reman motor that was installed in 2008 by Porsche. My motor has the larger single row bearing used in the M97. These bearings are non serviceable with the engine together, and with the extremely low failure rate, I would leave the bearing alone. You may also have this bearing; compare to this: Porsche Remanufactured Engine Info and Name This IMS - Rennlist - Porsche Discussion Forums

Ill be making a tool today to attempt a re-seating. I will use a large socket against the inner race and a coupling nut and threaded rod to gently pull the pin back through. This will omit more force on the bearings. IF I do find its a lost cause, I am kinda looking forward to breaking the engine down. But would like to get one more season out of it before taking that time. Stay tuned folks!

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Thanks for that info sir!

The attempt to extract this bearing has led to microscopic dents where the ***** contact the races. This isn't good, and often leads to accelerated wear. The process to reinstall the bearing can also lead to these dents being placed on the opposing sides of the races, doubling the damage. It sucks that this happened, and I can't help a lot, because in all my years I've never seen someone do this before. Typically the bearing is noted as being larger than the access port in the case, and extraction isn't attempted. Everyday is a school day, and we never know what we'll see!

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This is the second one I've seen posted here in the last year. The other one was done by a "Porsche Specialist" and they didn't realize it was the larger bearing until after they had tried to pull it out. I don't remember how that one turned out but a rebuild was recommended by just about everybody.(Including Charles) The "Porsche Specialist" offered to rebuild it I think. That would be the last place I'd trust with an M96 rebuild!

Wow! It seems there's lots of jumping to conclusions going on in the replies... IIRC, it doesn't take a lot of pressure to push that center bolt in. Depending on that amount of pressure I don't think there would be any damage to the bearing. Did you actually try to pull the Large bearing out before pushing the center stud in? If not, lets assume there's no damage... I don't see a problem with pulling the center stud back out so you can't reinstall the sealing flange. If there is at least 1 thread exposed, you may be able to get a pair of end nippers on it and slowly work it out enough to get your coupling threaded on. If not, how about a really strong magnet - once again, just to pull it far enough to get the coupling threaded on ? In any case, if you do get it back in position (and you haven't done anything else to damage the bearing - be honest with yourself or it'll cost you lots of $ in the long run) make sure you remove that outer seal on the bearing... Good luck

Thanks for all the input folks. As far as cost on a motor replacement if it did detonate, for me, its one of the cheapest cars I have owned. I would scrap/piece out the car then move onto the next high mileage project. Seems these motors have to be opened up occasionally just to deal with the wear and tear plastic timing chain bits that muck up the oil pan. My original reason for pulling the motor. It is fun learning from this group and all the resources out there. LN, Pelican, Raby and general online videos of fellow car folk experimenting. Good times!

So what's the plan? Did you actually try to pull the bearing out before realizing that it was the large bearing that can't be removed without splitting the case halves? Give us a little more info here...

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I did using a inner race removal tool. Hence the center pin removal. Once I get the pin in, Ill see how it feels.

Ooooo... In that case, I would take Jake Raby's advice - he speaks from experience...micro dents in the race. That bearing is going to eat itself which will ruin the engine. Seeing as you've already pulled the engine and want to learn about re-building it, just keep going. Putting it back together now is just going to set you back further - and cost you more time and money. Take your medicine...

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This isn't good. I thought you've stopped when the centre stud was pushed in. Did the bearing start to come out when you realized it won't clear the hole?

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Oh no...You will probably have damage the bearing if you got that forcing screw beyond hand tight.

The bearing is not made from cheese, it can handle some amount of force. Continue as you think and then inspect the bearing in 20-30k miles to see if it is wearing abnormally. DO NOT remove the seal! engine oil is not clean enough to use for ball bearing lubrication. Read what I've written in the IMS bearing thread...around post #490 something...

�Bearings are not made of cheese�... Nick L has spoken! So let it be written, so let it be done... By all means, ignore the rest of the advice you�ve been given, put it back together and drive it hard...

I have ordered up some bespoke parts to couple onto the M12x1.25 threaded center nipple and pull it through by the center race. Be a couple weeks before all the parts arrive (who knew 1.25 pitch fastener options were so rare). BUT I am leaning toward "Hold my beer" operation. That and I bought a 944 yesterday so I have a backup if things go south

Nick I don't agree with not removing the seal, if you think your ims is sat happy in your engine packed tight with grease sealed in by the bearing seals your having a laugh!! I've stripped a few of these engines, changes ims bearing etc, all you ever see when you pop the seals off is not grease , but trapped engine oil, the ims shaft is usually full of oil aswel, the ims is sat submerged in oil when the engine is off and I'd say the grease doesn't last long at all, so in my opinion along with a lot of others , it makes sense to increase the flow of oil into the situation instead of restricting it don't you think?

Two biggest Porsche M96 gurus and builders recommend you remove the IMS bearing seal.

I'll let you guys speculate what happens if a piece of chain guide finds it's way in between the *****. I think that makes it rather obvious why you don't want to remove the seal. You might want to ask the gurus how they have proven(not just speculate) the improved life time of the bearing...

Think I'll put my trust in one of the Gurus (that have seen it all) vs some guy named ...

Folks it's simple. Every major Porsche shop (Flat 6 Innovations, CallasRennsport, Hartech, etc.) all say that if you had to choose between using an OEM sealed bearing or an OEM unsealed bearing, unsealing the bearing would mitigate your chances of bearing failure. In other applications, sealed ball bearings would live a long time, but because of the characteristics (heat/cold cycles, high radial/axial load forces, etc.) within the inside of a high-performance engine like the Porsche M96, these bearings do wear quicker than other applications. It's well known that the M97 or 6305 bearing is very robust, but even still, all experts in the Porsche service industry advise pulling the outer grease seal and let the bearing be lubricated by fresh engine oil. Since working with Flat 6 Innovations, I've seen hundreds of images of outer seals being removed from IMS bearings. Every single bearing had it's original greased washed out.

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Not to mention that every single Retrofit bearing has no seals on either side, not to mention many other brands outside of LN.

This is 5min of searching the forum. Still confident that no seal is a good idea? https://rennlist.com/forums/996-foru...30k-miles.html https://rennlist.com/forums/996-foru...e-i-think.html https://rennlist.com/forums/996-foru...n-bearing.html

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This makes me face-palm. A properly greased bearing looks dry to the untrained eye, there is not much lubrication needed. The fact that you found a 'dry' but otherwise good bearing confirms that lubrication have been sufficient. If lubrication was insufficient you would have(found a broken bearing) done more than just remove the seal...

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Don't forget to use hand-san afterward. It's the 2020 thing to do! Well, not sure about that Nick. I've never tried to come across as some expert, but I don't have my head in the sand either. Here are a few images from bearing manufacturers: Never said anything about "dry" in my comment. That's you typing words into my mouth. I said "grease washed out"! I've worked with Flat 6 Innovations to produce educational content and have personally witnessed hundreds of cases (on-site and through examining images in a digital archive) where the original grease was "WASHED" out by engine oil that ingressed through the bearing outer seal. This was nasty, dark "cooked" oil, not fresh oil. When they pulled my 6204, nasty oil was filled in the shaft. I've also witnessed many engine failures associated with IMS bearing failure. We're just now finishing up a series on YouTube. You should check it out sometime.

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There's more to the equation, but don't take my word for it. Here's a quick overview of the reasons for bearing failure from their perspective.

I've worked in bearing production, a 6204 is never filled by hand with some hand tool like in the picture. The picture you see above is commercial material, they need to show the grease, you know. It would look weird for many if you don't see it and it says 'grease filled'. A sealed bearing is filled with aprox. 30% of the void space. Imagine this 30% being evenly distributed after 5-600h in 80-100c temp...there will just be a thin film left. Below is a pictures of a new SKF 6204 E2 2Z (double shielded, I didn't have a sealed at home). Can you see loads of grease in there? Note that the ball cage is a polymer which have almost the same color as the grease. A sealed bearing cost less than 20$ if you want to see yourself. I understand that the seals can fail and that is a different story.....

In the debate about whether to leave or remove the seal - I think it should be remembered that unusually it is the centre of the bearing that remains stationary and the outside that revolves around it and this applies a higher centrifugal force to any debris that might be present. I think the argument that it is better to keep the seal in case so me other major piece of metal failure is in the vicinity is weak. If that were the case the likelihood is for it to become tangled up in the chain and break it, caught under a cam lobe, stuck up a bore or something else that requires an engine rebuild anyway. bearings have been open in gearboxes and camchain tensioner bearings for decades without any problems.

It's almost time for Nick to create another alias to get behind him and continue this argument...

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Last time I checked the people you are slamming are the same ones that are making the forum that you are using for such behavior possible. As a Rennlist paid supporter I find your conduct completely disrespectful to this entire forum. Look at who sponsors this forum- LN Engineering, look at who you continually slam with your passive aggressive statements. At least have the intestinal fortitude to direct your statements by name, don't just say "some expert". My achievements with these engines, and the developments that have saved them are written in stone. Nothing you say will take that away. Nothing you do will matter, because you are, and will remain insignificant. You have done nothing to further these engines, and you hide behind a keyboard as an internet character with zero personal accomplishments in regard to the Porsche M9X engine.

I find your response �rather shocking� as well � do you work for Porsche customer relations or something? To put the record straight - I have never stated that the bearing is full of grease (meaning it was crammed full) I am a professionally qualified chartered engineer and know very well you leave an air space. If a bearing is supposed to have say 60% grease in it and you receive one with 30% grease it is not full it is half filled. If it is meant to have 60% it is correctly full of the right amount of grease. If it is crammed to occupy all the space it is over filled. Playing with words people use to describe this situation is rather pathetic � especially when however much grease is inside then seeps out to be gradually replaced with oil over time - so that it starts out with grease in it that then depletes to be replaced with engine oil. So what is best then � grease, half grease and oil, oil. Are you denying that the grease seeps out � if so you are delusional if not you are admitting it was designed in the knowledge that it will eventually run with oil and in that case your argument about fuel contamination is totally defeated. Have you ever seen the oil retained inside the shaft � very old carcinogenic rubbish that also seeps back into the bearing and out again (by the way � anyone getting near it � wear protective gloves it is seriously bad stuff). By the way - I don't make any videos with Jake or anyone else and am not part of the Knowledge Gruppe. By the way - the 6305 lasts perfectly well when lubricated by splash oil � so in my experience you are wrong. Your quote �There is one big expert in the market who tells you to keep the seal in place, Porsche. Porsche makes money when you are a happy customer and buys a new product from them. All other so-called big experts makes money from rebuilding your broken engine�. Can I correct that na�ve statement - When Porsche made their money was from selling a product that can fail in greater than acceptable numbers and mileages (I think that�s why the Class case in the USA against them was won). It is a shame they then charge for a replacement engine to repair the fault or highly priced internal replacement parts and did nothing else voluntarily for owners stuck with the problem. When the new IMS shaft was beginning to be popular as a replacement for the old one - Porsche put the price UP (not down). You suggest it is OK to use a bearing for a cam chain tensioner on the basis �because it works� in that case since the USA class action showed it did not �work� - the small IMS sealed bearing clearly �does not work� destroying your argument with your own illogic. Are you saying there is nothing wrong with Porsche's original design? If so why did they change it later on for the 6305 bearing. How many sealed bearings have you seen worn out? How many have you checked that have now completed more miles without a seal than the original bearing did with a seal? There are plenty of engines with ball bearings running lubricated from the engine oil that have no problems whatsoever as long as they are large enough for the loads applied which the old small bearing simply was not and there are plenty running with splash oil perfectly well - usually developed, manufactured and supplied because of lack of confidence and evidential failures that the original was not good enough by comparatively minute specialists businesses bravely trying to provide a better solution for their customers than Porsche did after taking their profit from the original sale - and they should be supported not vilified. It makes me wonder who you think the experts are � those that designed and made a part that can fail or those that provided at least as good if not a better solution? Baz

Sir, you can try to wind me up, but it's not going to work! I know your intention is to stir the pot. I've spent my life in broadcast communications and educational technology and have worked with hundreds (possibly thousands) of brilliant people from all types of disciplines/industries to produce media to help people learn difficult and challenging subjects. Apparently, you have no clue about the role of an educational producer/technologist and so you need to put a cork in it. All I've seen you do here on this forum is agitate and troll people like Barry Hart (Hartech) and Skip (Porsche Gold Master Technician) as well as Rennlist sponsors - Jake Raby (Flat 6 Innovations) and Charles Navarro (LN Engineering). You seem to have an axe to grind. Own it!

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Well said Jake. Your contributions to this forum have proven to be invaluable to many members of this forum and beyond. Thank you for that. Probably best to just not respond to this idiot and perpetuate his insanity.

I just want to thank members like FSI, Hartech, Skip, and LN for sticking around and sharing their time with us. I know when I first got my 996 I had my own opinions about what I would do. One thing I've learned in my career is knowing what you don't know is just as important as knowing what you know. Thank you for dealing with us, even when we don't even know what we don't know.

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True...true

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Thank you and others. The fact that we have to PAY to come here and be ridiculed by people like this is ridiculous. I just paid my 350.00 for another month to have the "privilege" to come here, so I can be told that I am wrong, and basically stupid by a person who has done nothing, and is nothing in the Porsche industry. Try that on for size sometime. It would be like paying 350 bucks per month for your internet service, and every time you turn on the PC a huge red screen comes up that reminds you how stupid you are for doing so. We get to pay for punishment, just so we can come here to take up for ourselves. Why? Because people won't police themselves, and take care of those among them that are creating this crap. It really makes no sense to me. Why I continue to pay it, also makes no sense to me. What makes less sense is why I even open up these pages. We rate two threads per month here to taut our products, but I never use them, because doing so just starts more crap that I don't have time to deal with, from characters like this Nick_L guy. Thanks to those who appreciate what we do enough to state it, and support it. You are few and far between, and I appreciate you.

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I agree 100% !! I don't have the vocabulary or patience to "Internet debate" with someone like Nick_L , but I'm glad you and Barry Hart do. His opinions are very detrimental to the Technical correctness of this forum. He lost all credibility for any Porsche engine knowledge when he stated that the oil pump drive shaft (pictured below) was designed by Porsche to intentionally break. Any Tech, gearhead, expert, or just mechanically inclined person knows this is blatantly false. And to those who are not mechanically inclined, if this oil pump drive breaks, the engine will self-destruct in a matter of seconds !! This is not just for M96 engines, but ALL engines !! I don't have to pay $350 to come here to argue with someone like Nick_L , as I'm just under the radar ( as far as requirements/threads/for sale adds), but am limited to "Technical only" threads that provide technical information and procedures and knowledge to the forum. I'll probably have to pay the $350 before too long as I have other things planned to help make the M96 engine a more bulletproof engine.. was NOT "designed by Porsche to break" as on record stated by Nick_L

Enjoy it for as long as you can. Nothing like having to pay to be hated, for giving away FREE information.

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Yes, a BIG THANK YOU! Imagine if we where stuck here with just Nick, the Dick with a bone to Pick ...LOL!

Thank you x996 to FSI, Hartech, Skip, and LN. Your passion for educating and helping others is inspiring to me. I only wish I had as much to contribute as you gentlemen do. Just chiming in because this needs to be seen - you have far more supporters than you do detractors. Sadly, detractors are louder..

Real simple: Nick_l I respectfully disagree with your position related to the I.m.s bearing.

FYI- The last time I had an engine come here that had a failure of an LN IMS Retrofit bearing was 2013. In that case LN provided an IMS Solution and a replacement IMS shaft to the customer without being asked to do so. Further, the owner of that engine didn't have a proper pre- qualification performed, and his old bearing was already failing; which was a disaster waiting for the replacement bearing that likely led to it's demise. I see a ton of engines come here with LN IMSB retrofits that have suffered other failures, primarily cylinder bore scoring. Not that these things are related to the IMSB, but more that the engines are not being properly qualified, and scoring then occurs later because the installer failed to check the engine for bore scoring before performing the IMSR procedure. He has targeted every person on these forums that is a vendor, or is well- respected by the group. It is pretty clear why he is here, and it isn't to help anyone. Why is he even here? What's his motivation? I know.

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This is absolutely true. Don�t let the BS get to you. Why people can�t be civil is beyond me. Good people trying to help good people is never wrong. Thanks for all you do.

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Diagnosing and replacing scavenge pumps ( if that was even your problem ) would give you about $150 (around 6hrs labor) before taxes in "Wrench-Cred" at a Porsche Dealership. That's not much in the grand scheme of things. It will be a "cold day in Hell" before you EVER can produce an Engineering document/tech document or anything else ,from Porsche or any other Manufacture, that says" the oil pump drive is designed to break"..Prove it !

If someone with lots of documented experience would show up and debate the issue with Jake or Baz or Skip then I might consider listening. ...or Bobby(I couldn't leave him out) But when someone who refuses to show documented knowledge of what they're discussing attacks those with MANY years of documented proof, I ignore them. Unless you prove your knowledge, you're just anonymous BS in my book. A Baz-Jake-Skip disagreement might be interesting...but I really doubt we'll see one. At least if we did it would be civilized! Porsche being an expert on roller bearings is on par with Ludwig D�rr being an expert in hydrogen. It works great...until it suddenly doesn't. At least the IMS bearing doesn't kill when it fails.

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Thank you, brotha!

No, because we are all professionals, and we appreciate the other person's view- even if it doesn't align with our own. At times each of us learn something from the other guy, and we are grateful for the opposing views, as we all know that the other guy came up with that point of view from his own direct experience. Nick_L has never built one of these engines. He can only prove awe wrong with photos of his hands inside one, and I want to see his face in the same photo. To this point he is some guy in his mom's basement that probably drives a Prius, and can't change his own oil.

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Yes, y�all are!

I've removed a few posts that were simply argumentative and disrespectful. Although it's fine to offer a differing opinion, degrading the conversation is not acceptable. Nick_L, you've made your point, but now it's coming across as a vendetta, something that isn't tolerated here. Move on, please. Thank you.

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Thanks for stepping in Mark. For a thread that was about the IMSB center shaft, this went way off-center

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Yep, I agree too...we NEED professionals like Baz, Jake, Charles, and Skip on Rennlist. Can you imagine this place without them? We'd be a bunch of blind guides!

Got an update for you folks. Parts came in yesterday. After cutting down the threaded rod and finding the appropriate socket, it was a 5 minute job to get the pin back into place. First image is pin connected to coupler. 2nd is the assembly of all parts. 3rd is the pin back in its inner race seat.

Good result, congrats! Now please tell us if you had tried to pull out the bearing using a slide hammer or removal tool before you pushed the center pin towards the inside of the IMS or wether that was only the first step to fit a slide hammer that would have gripped the ims bearing from behind. Curious mind wants to know.

@hardtailer Yessir I did. But not with the center pin. I pushed it in first and attempted an extraction with a bearing puller on the center race. Once that failed, I inspected closer and consulted this list, several images and books to compare what I was dealing with. With little info on the reman engine IMS mod that I came across, I naively went at it. But, hopefully quit and learned the situation before too much damage. So, onto the cam timing and re-installation after installing new chain guides and cleaning up the lifters. Any info on reman changes on that front would be helpful as I plan on learning from this.

So you're going to go ahead and reassemble with with the compromised bearing? Then what, sell the car before it self destructs? I wonder how many more of these time-bombs are out there...

Good luck with your reassembly! Sorry I have no rebuild expertise to add. I would strongly suggest you decrease your oil change interval to watch for metal bits coming from the bearing when it fails. Get a magnetic drain plug. Inspect every filter. It seems the time frame will depend on the extent of the damage.

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So do you yourself think that the force you exertet onto the center race with the puller was so great that earlier mentioned microscopic damage to the b@ll bearings has been done? Can you show us a picture of your puller? I'm having a hard time imagining how you can fit a puller to the inner race without having to knock the center stud all the way into the IMS. (Or how to get it back afterwards and make it look like in your first picture which was taken after the removal attempt as I understand?) So many questions