RND Roller Bearing IMS Kit?

I recently purchased a 2004 C4S tiptronic and had the dealer replace the IMS bearing as a preventative measure. They quoted me for an "LN Bearing", which I took to mean the typical ceramic bearing. The final service printout also says "LN Bearing." But the certificate I received shows they actually used an RND Roller Bearing -- http://rndengines.com/roller-bearing-ims-retrofit-kit/ Now I'm pissed and want to go back to the dealer to complain that I was misled. But the confusing part is that LN Engineering does list the RND bearing on their website as a "lower cost" alternative to the LN Pro ceramic bearing -- http://lnengineering.com/products/im...rofit-kit.html . This is even more confusing because the RND bearing is listed at the same $799 price as the LN Pro bearing. So what's the deal with this roller bearing part? I did a search and did not find out much, other than a few pissing matches and blown up threads. From what I can tell, the idea is that the roller bearing is technically more durable than a ball bearing, but the downside is questionable thrust loads -- http://986forum.com/forums/performan...s-bearing.html So what do folks think? Is this worth going back and making a stink with the dealer and try to have them redo it with the LN Pro?

I don't know what to say, but you've definitely posted in the right place to get some answers.

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I would say that if you were sold one thing but delivered another, then yes you need to go back to the dealer and hold them accountable. At least by your description, however, it sounds like a grey area. Technically it is an LN bearing so you got just that, but I think it could be easily argued that your interpretation is the common definition/expectation of "LN bearing". The question then, however, is what you want them to do? For me I wouldn't want them to touch it again since they already cut corners (in my opinion). I'd get local quotes for the roller vs ball install, then I'd go for a full refund or at least the difference in your example quotes. Next is what you want to do about the bearing you have now. You'll probably get some entertaining and interesting response and maybe a few booby pics I can't offer anything about roller vs ball for this application, it's way over my head. If you do go through pulling the bearing and putting a new one in again, I would suggest that you consider the Solution. It's more expensive, but it does seem to be the best option out there.

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I am guessing an estimate listing the parts & labor was presented for your review/approval BEFORE the work was started. Either you initialed/signed/dated a piece of paper or gave a verbal OK via phone. If this was the case, then the shop is covered. N.B. It was incumbent upon you to ask questions/clarify/verify BEFORE any work was done

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Thanks for everyone's thoughts. I was not presented with a formal quote with the parts list, just messages regarding the "LN Engineering IMS bearing." I was not even aware that LN sold other types of bearings. When I see LN bearing, that means to me a bearing made by LN, not another brand/type sold by them. I will bring this up with dealer and see what they say.

Right or wrong, I felt more comfortable with a roller bearing in this application so used the RND bearing to replace mine. So I chose the roller bearing over the ball bearing replacements. And yes, if I had understood the installation process a little better I probably would have opted for the Solution instead. I didn't think it was suitable for DIY at the time.

This is a blessing in disguise for you. I have the EPS cylindrical/roller "eternal" bearing in my car and have put about 1200 miles on the car since install. No issues. Cylindrical bearings do very well in this application, despite whatever fear mongering comments you may have read regarding their inferior thrust load. I would not put out any negative energy or waste any time on this... Be glad you saved some dough.

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Thanks for the reply. Can you explain why you thought the roller was better in this application? Feel free to PM me so this thread doesn't blow up. The dealer of course says that the roller is better, so that's why they used it. But I suspect they get a better deal on the RDS, which is why they are inclined to use it. Regardless, I expect the RDS to be better than stock, and any risk is negligible. It's just confusing that RDS appears to be a partnership between Raby (Flat6) and Navarro (LN Engineering), but yet RDS doesn't use the LN ceramic bearing. Those names do give me confidence in the RDS bearing, however.

Well from looking at the RND engine website it says "IMS Retrofit". If you click the link on that website it takes you to the IMS Retrofit website which is the single row pro (ball bearing) developed by "LN and Flat6". So I don't think a roller bearing is standard in the RND engines!? I could be wrong, but...

So how many Porsches are still out there, 5, 10 , 15 years and tens and tens and tens of thousand of miles later...and are still on their original IMS bearing?

There is an interesting distinguishing feature on the various cylindrical roller bearing IMS retrofit kits. Some have a separate oil feed, some do not. Some require a hammer+punch to the oil pump to create the oil feed. Some..... So before we attribute positive results to all roller bearing IMS kits , perhaps we should differentiate them by design type, not just who sells them? "I have the EPS cylindrical/roller "eternal" bearing in my car and have put about 1200 miles on the car since install. No issues. Cylindrical bearings do very well in this application, despite whatever fear mongering comments you may have read regarding their inferior thrust load. " The new concern is out-of-round shafts causing sequential failures of ball bearing IMS kits on the same car.It would be interesting to know if roller bearing kits can solve this problem within certain o-o-r limits. The ultimate product still is The Soultion imho and of course, it has a dedicated oil feed from the spin-on filter adapter.

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Dedicated oil feed because the design requires it. Apples & oranges to compare this sleeve/journal type bearing with an anti-friction bearing of any design IMO.

I am Mech Eng.I understand that. The issue is some roller bearing kits have an oil feed,some just rely on the stock/splash.So they are different from each other.And that difference may determine their longevity, depending on the 'issues' with the shaft. "There is an interesting distinguishing feature on the various cylindrical roller bearing IMS retrofit kits. Some have a separate oil feed, some do not. Some require a hammer+punch to the oil pump to create the oil feed."

I went with the RND bearing. Did the dealership fill out and return the warranty card and original bearing? I personally do not think you have anything to be concerned about, especially if the original bearing had no issues. My perspective on the whole IMS bearing is that it needs to be looked at as a regular service item with interval replacements. B5 audi's the timing belts are mandatory, Ferrari 355's eat headers, RS4's have carbon build up issues. Most cars have a "quirk" just so happens that our cars have particuarly expensive motors relative to the value of the car. What I am getting at is the job of replacing the IMS is not exactly difficult. With the tools for the IMS and RMS the most difficult part of the job is physically removing and installing the transmission. The rest of the job is literally a sequence of unbolting and bolting parts on and off the car. Look at it as doing a timing belt or other interval service item. Or pay a premium and spend the money to do the pre qualification with an oil fed kit. For me I decided that spending 5-8k for pro shop to do the IMS was kinda like buying the lifetime warranty on an appliance. I don't really ever want an appliance for life. I don't really expect the motor on my 996 to last for life. At some point something other than the IMS will fail and I will need a rebuild or new motor. However I did want to see the bearing in the car I bought, cause you know, paranoia will destroy yah..... So I pulled the OEM bearing out, saw it was fine, did a little happy dance and put my car back together to go have some fun. If the bearing had not been fine I would have not passed go, and gone directly to wallet punishing jail. Now I worry about the AOS and coolant temps... I attribute all that to me being on the internetzzz drinking car forum cool aide and being informed just enough to see the bad more than the good. I have to remind myself that there are thousands 996 owners in the world who just drive the car. Those owners defer maintenance, think IMS is an acronym for international manatee society, and don't know that the 996 headlights can cause 993 owners to grimace. I have two professions, insurance and specialty bicycle retailer. I see lots of bad situations and quirky niche products. Those niche products can have two bad units out of a thousand and will cause an Internet uproar. I have to fight myself to not over insure and not dump product at the first little hiccup I see. Try to mitigate your loss exposure, but understand losses are going to happen.

Sounds to me like a completely legal, used car dealer screwing. I knew they would pick the cheapest option, but then again - I know used car dealers. It's made by LN, it's for an IMS, and it is a bearing. So, live with it - or don't, but you ain't getting anything from the dealer now that you drove it away.

I used to own a 98 M3. Everyone talked about fixing the oil pump nut. The nut could come lose and then the oil pump sprocket would come off, immediate oil pressure loss and major engine damage. So the fix was to drop the oil pan and update the nut with a locking mechanism. Sometimes I feel like the IMS is the same deal. The M3 oil pump nut is real. The IMS failures are real. But it doesn't happen to many people as a percentage. I bought my car with 47k and now have 58k. The engine runs very smooth and quite. When the clutch starts slipping, I will most likely update the IMS bearing. For now I am just doing UOAs and checking the filter and magnetic drain plug.

Thanks for everyone's input. At this point, the RND bearing seems "legit" enough for me. I also note that while the dealer (a Premier Porsche dealer) was doing the IMS, they went ahead and replaced, at their own cost, the front strut tops because they noticed they were worn. This leads me to believe that they must believe in the RND bearing, as it doesn't make sense to shave a few hundred bucks in using a cheaper bearing when they went ahead and fixed other things on their own dime. Regardless, I will now go out and enjoy the car!

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I have no idea, but I will say that my prior cars were a 2002 Subaru WRX, 2004 BMW 330ci, and a 2012 Mini Clubman John Cooper Works. People say forums overblow issues, but I frequented the very active forums for all of these cars, and have never seen as many posts regarding blown engines that I see on this 996 forum -- be it IMS, bore scoring or some other failure. The closest issue was for the Mini, which had a problematic timing belt which could lead to catastrophic engine failure if you ignored it. But even then, you can hear a cold start "death rattle" in sufficient time to shut off and save the engine. That said, I still went and bought my 996 knowing that I would immediately replace the IMS as a PM, and enjoy the car worry free. Just couldn't pass up the best bargain in the sports car world right now!

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I think you meant chain.

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you owned a subaru and was on subaru forums and didn't hear about engine blowing up? the 2.5 subaru boxster motor is a ticking time bomb itself. eats head gaskets. pistons cracking/breaking. had to do the head gaskets on my 06 wrx. but then again, I also doubled the horsepower and torque with mods.

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Are there any known documented numbers of thrust loads on the IMSB in operation? Or are we all pretty much just guessing on the importance of thrust load capacity? I called EPS and had a lengthy talk with one of their lead techs. Highlights of that conversation: He told me the oil spash from the location of the IMSB was already ample lubrication and that "hole punch" oil feed was basically an optional measure for those who felt the need to have pressurized oil feed to the bearing. And that the thrust load capacity of the cylindrical bearing was more than enough to handle what comes its way in the IMS application and that the much higher vertical load capacity of the bearing would make failure much less likely in an engine where there the IMS shaft has the type of runout that could potentially wreak havoc on roller bearings. They've sold thousands of their roller bearing kits going back two years and not had a single failure reported to them. Arguing that a deep groove ball bearing is better in the IMS application than a cylindrical/roller bearing simply because Porsche designed it that way is poor logic IMHO, as this part is clearly at the center of a huge problem that many acknowledge is a fundamental design weakness in these engines. Whether the root of the problem is a batch of bad bearings or IMS shafts with roll out becomes secondary. IMHO, a roller bearing combats both of those possible root causes better than a ball bearing.

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Right on! I bet it runs and drives great.

Ball vs. Roller thrust capacity = this is something you can read in any bearing spec chart. The diminished thrust capacity of the Roller vs. ball is a fact. How significant that is in the IMSB application is empirically unknown. There are adaptations to increase the thrust capacity of the roller bearing and some cylindrical roller bearing IMS kits have this feature - RND for example.In these specifically enhanced bearings ,it seems reasonable to presume the thrust issue has been resolved to a practically adequate degree ? The kits from EBay Taiwan do not have any enhanced thrust control - just a simple NUP204? bearing. Some seem to have added the thrust enhancing feature after the many lengthy discussions of the issue here. The field results with roller bearings have been (surprisingly?) good but unquantified and unverified. The other concern about rollers was heat generation. They create more heat than ball bearings. A supplementary oil feed would mitigate that but there is no data to quantify the significance of this effect. Then there is the o-o-r issue which ,to a degree, the roller may adress better thn a single row ball bearing. This seems to be the flavor of the month . It would be interesting to see a comparison of the features of RND, FVD, Vertex and other roller IMSB's.Marcus has produced a partial list. I just went with the recommendations of someone I trust. If it is good enough for Jake....I just spent well over $7k rebuilding the engine. If I had to confess it grenaded because I used an unproven bering after all this debate, the shame would be unbearable.

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Good points... and can't fault you for following Jake's advice. You and I are in the same boat in regards to engine investments... Best of luck to both of us.

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You might be alright keeping the RND bearing. So far I've read of two recent failures on the ceramic LN bearing. One at 20k and the other thread going right now at 30k miles. Has anyone with the RND bearing had a IMS failure? Reading all these threads makes my brain hurt, but with the cars getting a lot of mileage now post IMS "fixes," it's unsettling to see more than 1 LN ceramic bearing failure. Just figuring out which way to go myself. I would trust my mechanic and what they've seen.

"I would trust my mechanic and what they've seen" Why? The knowledge base on this subject is still developing and few mechanics have access to the latest discoveries.They know what new products are available but seldom bother to study the background forensic engineering that prompted the development of new products. Two recent developments are misaligned crankcase machining and run-out of the IMS.Ask your trusted mechanic about that ?You will probably get a blank look. Further ,few mechanics would bother to do the entire Pre-qualification check for IMSB replacement. Even if they did and found a few deficiencies, they or the owner may proceed with an IMSB replacement anyway. Then flip the car before a failure occurs ? I am not insulting your mechanic. The nuances of the IMSB subject just does not warrant the average mechanic's attention . That is why these threads make people's head hurt. If you want a simple answer ,it is called "The Solution". But we are still learning why it seems to be so much more successful. The runout theory is a good example of why The Solution is more effective and also why to a lesser extent(??) the roller bearing may be better than the ball bearing(for runout problems?) and a supplementary lubrication system with a roller bearing may or may not be better.

I also have the EPS roller bearing with the oil feed and installed it when I did my rebuild, it looks really robust and up to the job, and as far as I can see there isn't anything applying thrust load to the bearing , it just needs to be held in true so the chain and sprockets stay in line to stop the chain wondering off the sprocket, on the EPS system the ims can't go forward as the front end of the ims shaft has a plain bearing type arrangement that slots into the back of the oil pump and as far as I can see stops forward movement of the shaft (along with the thrust control washer behind the roller bearing at the rear of the shaft. Rearward movement of the shaft is controlled by the rear end face of the ims acting as a plain bearing against the ims flange which is partly the reason for the oil feed, there is a constant supply of pressure here. I would say though that the shaft just floats in position, there isn't anything pushing it forward or backward , there will be minimal loads as it keeps the shaft in check but it's not like it's got thrust loads the crank gets from the clutch and flywheel etc and the crank only has two relatively small thrust bearings taking that load, can't see why this set up wouldn't work, well fingers crossed anyway !!

I'm biased towards a roller bearing setup over a ceramic bb, but that's because I've read about ceramic ones getting chewed up but no rollers. Anyone know of a roller bearing failure?

Count me in as a participant in the Roller Bearing longevity experiment as I too have installed the EPS roller bearing with forced oil replacement for my original dual row IMS bearing. Original IMSB was wobbly and in need of removal and replacing after 100K miles of joy and servitude. Also I noticed that the kit did not include a decal like the LN alternative to paste on the chassis as evidence that an EPS Roller Bearing was installed.

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It is all a numbers game. I have seen the failure posts of the ceramic LN bearing also. But it is probably the most used bearing out there so it will have the most failures. It will be years until we see any of the newer ones fail, it at all. The good part about the internet is everyone can state their opinion, so here is mine - the inspection and the mechanic are much more important than which bearing you choose.

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How long has it been since you had yours swapped? Are you aware if there were signs of metal debris in your oil leading up to that, or have you noticed any since? I would expect the extent of debris leading up to the swap to be proportional to the amount of wobble... and by the time you see pieces big enough to visually identify as debris the damage is likely done. My guess would be you caught yours just in the nick of time. My car's IMSB came out at 94k and was seemingly perfect.

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Figured it was a given but I'm implying trusting a reputable mechanic who has done MANY IMS retrofits and is knowledgeable on the situation. We maybe just maybe might have a decent Porsche shop in the bay area or LA. I'm just guessing. Or as an enthusiast and someone with access to the internet I can tell a professional with way more experience what I think they should do. Hard choice.

Jaetee, to answer your question. I just installed mine. It's been a long-term project 5 month since initial breakdown. I did a breakdown of the motor which was stared by a failed AOS along with an oil pan reseal and oil change. I did not have the typical metal shavings in the oil. My oil was quite clean and I in fact had plastic bits in my oil filter bowl, filter and chunks in the bottom of the oil pan. So that prompted me to tear out the motor and do an inspection of the damage and the cleaning. Once inside I found the VareoCam tensioner pads (brown plastic) were eaten up, along with my IMS chain paddle (the black plastic). Out of curiosity I check my dual row IMS. Found it to be a bit too wobbly for my taste so I pulled it. Took one of the grease cover off and found no grease in the assembly, so I removed the IMSB and it looked like the pictured one below. Metal bits and shavings.. The inside of my IMS Shaft looked like silver glitter and grease had been splashed on the inter walls. So I could tell all the grease from the bearing had migrated there. After further inspection of the IMSB (dual row) 101K miles, it was evident to see the four grooved wear marks on it from were the bearing had been grinding. So I replaced it. After the cleaning and engine refresh I've got new AOS, new hydraulic lifters, new VareoCam tension chain pads, new IMS Roller bearing, new IMS chain paddle guard, all new engine seals, new lower temp thermostat, new motor fire wall, new belt tensioner, new chain rails, all new bearings on all 3 serpentine belt pulleys and now also installed a magnetic oil pan plug. Found out the big black pieces that were in my pan were left behind bits of a replaced set of Spark plug tubes that must have broken during removal. The shape of the bits and then looking closer at my spark plug tubes that were date of manufacture 5/09, when everything else on my engine was dated 99 was the evidence of the previous replacement. Guess you could say I got lucky that all the metal shavings were caught in the washed grease within the IMS shaft behind the bearing. I'm glad I inspected it and replaced the IMSB.

I had a similar issue but went(madly?) much further in the dismantling because of FOM concerns. The debris from your IMSB would have spread throughout the engine unless you had the full-flow oil filter upgrade. The concern is that bearing debris can lodge inside the engine before it gets to the oil filter and dislodge later. The stock filter may not catch this until it has already passed through the main or big end bearings. The Lifters may be particularly susceptible to blockage with the very fine debris that is often dismissed as sludge. Hopefully none of this applies to the engine-refresh you did. A total dismantling does give the benefit(?) of being able to make many small upgrades like ARP connecting rod & head bolts and oil pump drive shaft,pinning the IMS sprocket,checking for trueness,knock sensors,ultrasonic cleaning.crankshaft magnfluxing and so many other things that makes a full rebuild a financial fiasco - unless you plan to keep the car forever. Your replacement IMSB is the RND cylindrical roller bearing,right ?

That is correct Schnell. I did the deep cleaning the pinning of the IMS sprocket and the EFS roller bearing replacement.

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He means E P S One notable difference with EPS/RND is the RND offers no additional forced lubrication oilfeed on this particular bearing kit and says it is unnecessary on their bearing. http://imsretrofit.com/roller-bearings/

The "EPS" kit and thanks for the correction on the typo. You are correct the kit I got actually came with a slightly grooved Allen hex driver for the oil pump for additional oil feed. http://europeanpartssolution.com/pro...earing-repair/ So yeah I agree with you the difference is one has the added oil feed and the other doesn't.

This has been discussed in other threads at length but for the benefit of casual readers, EPS/Vertex reportedly now says the supplementary oil feed is optional. There are other differernces. The EPS IMS bolt, flange and thrust control is also different to RND. Unlike RND, EPS give no thrust specifications on their cylindrical roller bearing kit .If any of this detail is important to future users, more info is in Search ! One other point in favor of the cylindrical roller bearing kits for single row IMS cars is that the original LN IMSB tool kit (or a clone?)can be used to install them. Many Indies already have this LN original tool kit for LN#106-08. 13 . If they have low volume or a diy guy like me , they may be reluctant to also buy the recommended new tool for 106-08. 2.2 "Faultless" at over $700 MRSP($450 ? on Ebay), to install the better Single Row Pro Gen2 IMSB. They can buy a roller bearing kit for $500 or less, use their original tool that is already paid for - that is all it costs $500 max. The latest LN Single Row Pro bearing is $750,+the "Recommended"new tool for a total $1250+. If you find a used Faultless tool at a good price that would help a little . That $700+ price difference explains much of the interest in the roller bearing kits I suggest. Has anyone successfully installed the latest LN Single Row Pro Gen2 with the original LN tool kit ? I ask because by my understanding ,it can be done but I don't recall reading any diy accounts of it being used.In theory ,the new Faultless tool minimizes the risk of a bad installation.Compressing the spring-wire locking ring without a special tapered sleeve would be 'difficult' ?? See the LN chart here: http://lnengineering.com/products/fe...-106-0822.html Single row Pro installation video is here: https://vimeo.com/84432223