Intermediate Shaft (IMS) Upgrade & Retrofit Kits. We are UK agents for LN Engineering, a leader in the Porsche aftermarket for high performance products and services. Price may vary on make and model of your Porsche. Doing an IMS retrofit procedure isn’t much harder than doing an IMS flange reseal, so if the shop you’re thinking of using has done these procedures (as most that are familiar with Boxster, Cayman, or 911s are), a retrofit kit installation won’t be any more difficult than this. If all else fails, any Porsche dealership should be able to carry out this procedure. To date, over 50% of retrofit procedures have been carried out by Porsche dealerships. How do you identify an impending IMS failure? As you can see in the video above, inspection of the IMS bearing at regular intervals, say whenever an RMS leak is being fixed or installing a clutch, can help in evaluating the condition of your IMS. There are not many warning signs of an impending IMS failure short of a “death rattle” that occurs as the bearing fails and comes apart. If caught early enough, a leak at the IMS hub flange may be signs of a failing bearing, but can be improperly identified as an RMS leak at times. If doing a rear main seal (RMS), it’s recommended to do an IMS retrofit at the same time, as the majority of the labor is identical to that of performing the RMS service. Why do intermediate shafts fail (or rather, why do the bearings fail)? Thanks to a fellow Porsche Boxster owner who is also a retired bearing engineer who worked for Timken Bearing, we have gained much insight towards the root causes of intermediate shaft failures. Here’s the reader’s digest version of his bearing analysis and how LN Engineering has used this information in developing its IMS solutions. By their estimates, they figure a 90% survival rate of the bearing used in the IMS at 90,000 miles – resulting in a staggering 10% failure rate called the L. Assuming an average speed of 60mph in top gear. There are two configurations of intermediate shafts the major variations are in the drive, where the early have a bicycle chain style sprocket where the later is a gear type sprocket. The other differences are in the intermediate shaft bearing configurations, with three bearing configurations – an early dual row, single row, then final version, with the larger single row bearing. Both intermediate shaft assemblies use a bearing support visible as a small stud from the exterior of the engine in the center of the IMS hub flange. This stud has a flange that centers and rests on the inboard side of the bearing and torques the inner race to the stationary IMS hub flange. The outer race is allowed to rotate which allows the IMS to rotate. A few problems stem from the support stud which is undercut for an o-ring to keep oil from leaking out of the IMS hub flange. This severely weakens the stud as it is undercut deeper than the threads by a good margin. The main problem stems from the use of a sealed bearing. Although the seals are intended to keep oil out of the IMS tube and keep the permanent lubricant in the bearing, neither happens. On engines observant of factory recommended long drain intervals, oil heavily laden from fuel or just dirty from too long of drain intervals provides poor lubrication for the IMS bearing. 002% water in the oil can reduce bearing life. By up to 48%. Higher moisture levels up to 6% can reduce bearing life by up to 83%. Excessive oil temperatures also have a negative effect on bearing life – the life of the permanent lubricant used in these bearings is cut in half by every 18F increase in temperature. From an uncontaminated life of up to 30 years at 86F to a useful life of only 90 days at 212F! This is why the bearing engineer recommended removing the seal and allowing the engine oil to lubricate the bearing, and why frequent changes are so important. Oils high in ZDDP and moly further improve longevity as suggested in the article referenced above. More info about ball bearings can be found here. Now it gets more technical…. Where the exact reason for IMS failures cannot be known for sure, in the bearing analysis it was noted that bearings used in the IMS position are unusual in that they are double sealed and have outer race rotation. Bearings were found to be void of grease and had light oil in them and wear patterns in the ball grooves indicate marginal lubrication due to the relatively low viscosity of motor oil compared to grease. In addition, conventional class 1 bearings, like the 52100-series bearing steel used in the factory bearings, is typically only stable to 250F, suffering from fatigue and weakening exposed to elevated engine temperatures that slowly affect the bearing’s strength over its lifespan. Attempting to reduce engine coolant operating temperatures directly reduces oil temperatures, further improving bearing life! That’s why trying to lower the coolant AND oil temperature is so important! Computer simulation of the 6204 bearing showed that only three balls are under load at any given time. Hertz stress is moderate. Lube film thickness is very small. Ideally it should be greater than the worst surface finish. Speed is not high enough to develop an elastohydrodynamic film to overcome surface finish/film issue. Fatigue life is high due to relative light load but with no EHD film there will be metal/metal contact and wear. With only three balls under load at any one time the unloaded balls will be dragged around by the ball separator. When a ball leaves the loaded zone it will tend to be driven into the separator pocket. The engineers initial thoughts were that the ball-separator failure led to bearing collapse, but after analysis of said IMS bearings, it would appear that bearing wear/fatigue spalls lead to separator wear and outer race failure. Separator failure and bearing collapse causes catastrophic failure of the mounting bolt(s) and IMS/timing chain components. The first recommendation was to use a bearing without seals and secondly to use a higher viscosity oil (with greater film strength). More frequent changes will also improve lubrication quality. An oil with extreme pressure additives like Moly might also further assist in increasing bearing life. Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven like they were stolen. Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full protential. Further recommendations by the retired Timken engineer are evident in the design of LN Engineerings IMS upgrade and retrofit kits. Shown below are typical IMS failures. Worn ball bearings from dual-row 6204 bearing (3.4 996, 75,000 mi). Worn inner race from dual-row 6204 bearing (3.4 996, 75,000 mi). Why do some used bearings look normal and others have wear on the outside? Shown above are three used dual row bearings, all in good condition. A normal bearing shown at far right, as we would expect to find. Note two left bearings have wear on the outside diameter of the bearing. At best, we attribute this to tolerances in the manufacturing of the intermediate shaft itself, measured as ovality, taper, or any other variations that might allow a bearing to actually move and loose its press fit. It may be that part of the issue with failing IMS bearings are that the intermediate shafts themselves are not “all made equal”, where some do not have the proper press-fit on the bearing or others do not have the bearings centered in the shaft! Why doesn’t the bearing on the other end of the intermediate shaft fail? Well, there isn’t technically a bearing. The other end of the intermediate shaft rides in a bore of raw aluminum, splash oiled. Earlier aircooled Porsches and even later water-cooled GT2, GT3, and Turbo engines use split plain bearings (actually a VW Type 1 double-thrust camshaft bearing) that are oil fed on both ends of the shaft, with decades of proven reliability. How is the IMS Bearing lubricated? As supplied, the original IMS bearing employed a sealed bearing and relied on a permanent lubricant (grease) to lubricate the bearing. (Similar to the sealed bearing that fails in the gearboxes found in MY97-08 5 and 6 speed manual). At this point, the seal fails to retain the permanent grease, which is washed out by the engine oil. When this happens, the little amount of oil in the bearing is not sufficient to lubricate AND cool the bearing, leading to accelerated wear. Several solutions have been suggested from more frequent replacement of the bearing and or seal and a lubrication schedule to replenish the permanent grease. With our IMS Retrofit and IMS Upgrade, we chose to use a ceramic hybrid bearing which requires less lubrication and is designed specifically for poor lubrication environments. Coupled with the lack of grease seals, the new bearing is lubricated by splash as well as submersion lubrication (depending on operating conditions). With its longer service life under these conditions, the ceramic bearing is intended to be a long-term solution and a permanent fix. What kind of bearings do you use for the IMS Upgrade or Retrofit kits? Based off of the knowledge gained from our bearing analysis of both factory single and double-row IMS bearings and significant research, we’ve employed a custom ceramic hybrid bearing, featuring precision premium Japanese-made tool steel races and genuine USA-made Timken or SKF-sourced sintered silicon nitride ultra-low friction roller balls (based on availability). WE DO NOT USE CHINESE BEARINGS – BEWARE OF HIGH FAILURE RATES ON CHINESE CERAMICS! We use exclusively ceramic hybrid bearings on both our IMS upgrade and retrofit kits. On average up to thirty times more expensive than conventional steel ball bearings, the benefits far outweigh the cost. Recent improvements in purity and grain structure have given silicon nitride a high stress fatigue life equal to, or better than, that of bearing steels. Some tests have shown life 3 to 5 times that of M-50 steel. Performs up to 15 times longer in poor lubrication environments (like suggested by the bearing analysis above) as compared to steel. Less maintenance – Due to a minimum level of Adhesive Wear, bearing components and lubricants last much longer, saving you expensive service and repair time. High Hot Strength – High compressive and flexural strength over a wide temperature range. Lends itself for use to 2200 degrees F. Low Density – Specific density of 3.2 compared to 7.8 for steel. At high bearing operating speeds, the bearing balls have a centrifugal force which may exceed the external loads on the bearing. The low density of ceramics can reduce this load considerably. High Hardness – While bearing steel is in the RC 58-64 hardness range, silicon nitride has a hardness of RC 75-80 and offers excellent wear resistance and resistance to denting or flat-spotting. Coefficient of Friction – Silicon nitride has a coefficient of friction which is significantly lower, especially under marginal lubrication conditions. It also exhibits better resistance to scuffing and seizing than bearing steel. Corrosion Resistance – Silicon nitride is unaffected by most common corrosive agents, and is well-suited for use in hot corrosive atmospheres, or where lubricants have been known to attack conventional bearing steels. What is the IMS Upgrade? To resolve these known IMS problems, we have engineered our IMS upgrade with a billet chromoly steel hub flange, an increased diameter bearing support/retainer (also manufactured out of chromoly), also providing increased bearing area and dynamic load capacity of almost 5,000 lbs. With our triple bearing – compared to 2200 lbs. For the single, 3060 lbs. For the dual row, and 3650 lbs for the MY06 and later single row. In addition, we use Porsche’s revised seal to ensure leak free operation and we permanently seal the ims tube (behind the bearings) to prevent it from filling with oil allowing us to use open bearings for improved cooling and lubrication. We offer this service for all intermediate shafts MY97 through MY08. MY06-08 shafts receive a new OE Porsche flange, seal, and IMS, as well as an updated ceramic hybrid bearing and the shaft also goes through the same processes as earlier single and dual row bearing intermediate shafts, receiving single updated larger bearing instead. By adding extra bearings and substantially strengthening the part, both causes for IMS failures are addressed. Use of our ceramic hybrid bearings further help to improve longevity and reliability. Smaller diameter rear pre-loaded bearings increase outer race velocity, promoting higher film strength and improved EHD lubrication with provided splash engine oil lubrication. IMS Upgrade shown on both the later gear-type (above) and earlier (bottom) bicycle-chain style sprocket IMS. IMS Upgrade shown on M97 intermediate shaft (below). What is the IMS Retrofit Kit? Unlike our IMS Upgrade which requires the IMS to be removed from the engine to be machined to accept our revised setup, the single and dual row IMS Retrofit Kits are designed to replace the original bearings with like sizes and with similar load ratings, without engine disassembly, and have been developed in partnership with Flat 6 Innovations, for both single and dual row bearing intermediate shafts. In a process originally developed, tested and used by Scott Slauson of Softronic. Extraction of the dual row bearing was found to be possible, involving collapse of the internal wire lock that retains the bearings, requiring great force be applied to the bearing to facilitate extraction. Above photo courtesy of Wayne Dempsey, Pelican Parts. Once the bearing is out, you are ready to install the new bearing. One trick to getting the new bearing in is to throw it along with the bearing driver tool in the freezer – this will shrink the bearing approximately. 0005, making installation even easier. Additionally, if you inspect the original bearing, you may find signs that the outer race has actually been spinning in the IMS housing. Alternatively, you can measure the housing bore for ovality. If that is the case, use Loctite high-temperature bearing mount sparingly on the outer race of the new bearing, then install. Once the new bearing has been driven in (shown above, using the driver tool shown, right), the new billet hub flange can be installed, best accomplished by using longer bolts to draw the flange into place. At this point, the 12-pt nut that goes on the new, larger diameter bearing support gets torqued. One installed, then you can replace the bolts with the proper microencapsulated bolts and torque. Shown below is the complete single row bearing IMS retrofit kit. We only supply the highest quality ceramic hybrid bearing currently available, with genuine Timken silicon nitride balls. We recommend scrolling back to the top of this page to learn more about why we have chosen these very expensive bearings over cheaper ones. The single row retrofit kit includes a direct replacement for the factory 6204 series bearing. On engines with a dual row bearing, significantly greater effort is needed to remove the bearing because there is an internal wire lock that has to be forced to compress before the bearing will come out. This differs from the single row which has an external snap ring that has to be removed first. Our tools and associated procedure allows you to safely remove the dual row bearing without stressing the crankcase or any internal components. Shown below is the dual row bearing IMS retrofit kit. The dual row retrofit kit includes a custom dual row bearing as a replacement for the factory dual row 6204 series bearing, which is now retained with a custom external snap ring or spiro-loc (as shown). Our kits replace the factory sealed bearing with a new, severe duty custom ceramic hybrid roller ball bearing for reduced friction and superior performance in poorly lubricated operating conditions and replaces the factory IMS flange hub, bearing support, and fastener with a stronger, revised billet chromoly assembly. The center bearing support also receives an increase in size and no longer is cut for the o-ring that keep engine oil from leaking out of the engine – we have relocated the o-ring to the IMS hub flange for added strength to the center stud & bearing support (comparison between our upgraded bearing support and the OE one shown at right). What is the cost of the kit and what does it include? Kits include the new bearing support, flange, bearing, retaining ring, and set of new OE Porsche microencapsulated bolts + fitting. What is the procedure for doing an intermediate shaft bearing retrofit kit? We do not recommend IMS retrofit kit installation as a do-it-yourself project – installation is best left to your trained independent mechanic or Porsche dealership. That said, typically the job is a billable 10-14 hours and average labor rates around the country are 0/hour. Later Tiptronic 911s require the engine and transmission to be removed together, so expect those cars to be very expensive when it comes time to do an IMS retrofit kit. Does installing an IMS retrofit or doing an IMS Upgrade make my engine immune to an IMS failure? It’s hard to answer that question. Porsche revised the design three times across the MY97 to MY08 M96 engine and eventually decided to eliminate the IMS completely from the new MY09 engines. It may be advisable to consider the IMS a service item, like a timing belt in many modern cars. Seeing that we started to see more MY05 engines with IMS failures in late 2009 as well as failures in MY06 (with revised 3rd gen bearing) in late 2010, that may suggest that bearing replacement (or inspection at bare minimum) should be considered every four years or 50,000 miles to 5 years or 60,000 miles, similar to many manufacturers’ powertrain warranties. That said, we’ve put the best bearings we can in our IMS Retrofit Kits and Upgrades to give your M96 the best fighting chance for a long service life. Currently we have three years of service of our IMS Retrofit and IMS Upgrades with zero failures and several thousand in service. Goodwill will be considered on a case by case scenario for rebuild or replacement of an engine if found that our IMS Upgrade or IMS Retrofit was the cause of engine failure by Flat 6 Innovations in the contiguous 48-United States. Google and the BBB are your friends. What happens if I’ve already had an intermediate shaft failure? Depending on how bad of a failure your engine has suffered, it may still be possible to extract the failed bearing and install a retrofit kit. Our retrofit kits are intended for preventative maintenance or fixing of bearings in the process of failing with excess wear, but that haven’t yet failed. If the original center stud / bearing support has broken, you’ll need our “Easy Out” adapter, which is part of the IMS Pro Tool Kit. If the inner race has failed and the balls have come out of the bearing, damaging the IMS (as shown below), we do not recommend doing the IMS retrofit procedure. This typically is the case with most single row IMS bearing failures, as this damage typically destroys the snap ring groove, preventing you to install a new snap ring to retain the new bearing. IF YOUR IMS LOOKS LIKE THIS, YOU SHOULD NOT CONSIDER AN IMS RETROFIT. The aftermath of a single row IMS bearing failure on a MY04 – complete disassembly and a rebuild is your only recourse at this point. Also, when damage is this extensive, installation of an IMS retrofit is not possible and the shaft itself is not usable. The engine will need to be torn down and alternate core IMS sourced (we offer rebuild cores, check with us on availability). Although it is possible to pull the bearing from the outer race using a Kukko 22-2 counterstay and 21-6 internal extractor or use extreme methods to get the failed bearing out, at this point a significant amount of debris has gone through the engine and there is also the high probability that the drive gear/sprocket will have moved and is backing off the shaft, possibly leading to other problems down the road. Make sure that you do not pull directly on the back of the case when using any Kukko counterstays. You’ll want to fabricate some sort of bushing to go in and apply the force of extracting the bearing directly on the IMS housing. The aftermath of a dual row IMS bearing failure – complete disassembly and a rebuild is your only recourse at this point. Photo courtesy of Renntech. AGAIN, IF YOUR IMS LOOKS LIKE THIS, YOU SHOULD NOT CONSIDER AN IMS RETROFIT. Available for all models and engine size. Vat to be added to the list prices. Old unit must be. Fully Rebuilt with 2 year. (supply & fit) from. Recovery of your vehicle also available call. 911, Cayenne, Boxster, Cayman etc. We have been supplying and fitting engines and gearboxes for over 20 years, and. We can supply and fit any Engine or Gearbox , for any vehicle make or model. We are AA approved and all our workshop mechanics are fully qualified with years experience. The item “PORSCHE 911 996 3.4 BOXSTER 986 2.5 2.7 3.2 Intermediate Shaft Upgrade kit & FIT” is in sale since Monday, August 21, 2017. This item is in the category “Vehicle Parts & Accessories\Car Parts\Engines & Engine Parts\Complete Engines”. The seller is “germanenginespecialists” and is located in Erith, Kent. This item can be shipped to United Kingdom.
- Brand: OE Spec
- Manufacturer Part Number: Does Not Apply
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