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hey there I just bought a '99 C4 and I put the last 6 digits of my VIN on the LN Engineering website and it came up
Production DateJun 2016
Car Year1999
Full Vehicle Identification Number624582
Installation DateAugust 27, 2016
Installed at mileage:86740
Installer / ShopEuropean Motorsport
is this your car???? funny mine is also dark blue but the receipts I got does not make sense with the LN info above
Oil leaked out due to IMS retrofit oil line
Has anyone heard of this issue? I searched and could find no evidence of it. But apparently it happened to my 996 resulting in hemorrhage of oil due to a failure of the line/hose that delivers oil to the retrofit IMS bearing on 2000 996. To fix requires back out transmission and fix/replace the failed oil line. I was told the original install of the IMS retrofit ran the oil line too close to engine manifold. Thankfully a major issue was resolved before serious damage.
Oil line was too close to hot manifold.
Repair summary.
Also with the L&N IMS Solution we wouldn't need to remove the transmission to replace the line, from the tech report, good thing you did and all the bolts were properly torqued.
hey there I just bought a '99 C4 and I put the last 6 digits of my VIN on the LN Engineering website and it came up
Production DateJun 2016
Car Year1999
Full Vehicle Identification Number624582
Installation DateAugust 27, 2016
Installed at mileage:86740
Installer / ShopEuropean Motorsport
is this your car???? funny mine is also dark blue but the receipts I got does not make sense with the LN info above
help!
It is common for the last six digits of the vin to be duplicated, even within a specific model year. It likely is not your vehicle if the information does not match. If there is ever any question, you can always submit a support ticket and we can often provide additional information as long as the person who registered the install supplied all the required information to us.
I had my 996 refurbished in 2017 and I cant remember if the IMS bearing was replaced. I have an invoice from SST Performance in PA that has since closed so I cant call them to ask. The invoice shows 3 bearings were replaced when I had the transmission rebuilt but shows no part numbers. Based on the other things changed and their prices, would it be correct in assuming that one of these bearings is the IMS?
I had my 996 refurbished in 2017 and I cant remember if the IMS bearing was replaced. I have an invoice from SST Performance in PA that has since closed so I cant call them to ask. The invoice shows 3 bearings were replaced when I had the transmission rebuilt but shows no part numbers. Based on the other things changed and their prices, would it be correct in assuming that one of these bearings is the IMS?
My assumption would be no. That looks like a very transmission-specific set of parts. Not even a clutch or pressure plate listed.
This is some seriously good information from one of our forum experts, thus it belongs in our 996 forum "official" IMSB thread. And I really wish forum members would quit posting in that other thread. It is old news and the OP should have posted in here.
The claims made by some about load ratings for their roller bearings are disingenuous. Regardless of brand, a particular size or type of ball or roller bearing will have a set rating for that bearing and can be verified by looking at any given manufacturer's catalog. Claims of 5, 10, or 12 times the strength is simply just not true.
The factory single row 6204 bearing a dynamic load capacity of 2900# with thrust max load rating of 1450#.
The dual row 4204/5204 has a dynamic load capacity of 4000# w/ thrust of 2000#.
The later non-serviceable 6305 bearing has a dynamic load capacity of 4,600# w/ thrust of 2300#.
The NJ or NU204 cylindrical bearing used in most roller bearing kits has a dynamic load capacity of 3750# with thrust max load rating of 375#. It is worth noting that although the cylindrical bearing has 29% higher load capacity, in thrust it has only 26% of the capacity of the deep groove single row 6204 bearing.
__________________
Charles Navarro
President, LN Engineering and Bilt Racing Service http://www.LNengineering.com
Home of Nickies Cylinders, IMS Retrofit, and IMS Solution
This is some seriously good information from one of our forum experts, thus it belongs in our 996 forum "official" IMSB thread. And I really wish forum members would quit posting in that other thread. It is old news and the OP should have posted in here.
The claims made by some about load ratings for their roller bearings are disingenuous. Regardless of brand, a particular size or type of ball or roller bearing will have a set rating for that bearing and can be verified by looking at any given manufacturer's catalog. Claims of 5, 10, or 12 times the strength is simply just not true.
The factory single row 6204 bearing a dynamic load capacity of 2900# with thrust max load rating of 1450#.
The dual row 4204/5204 has a dynamic load capacity of 4000# w/ thrust of 2000#.
The later non-serviceable 6305 bearing has a dynamic load capacity of 4,600# w/ thrust of 2300#.
The NJ or NU204 cylindrical bearing used in most roller bearing kits has a dynamic load capacity of 3750# with thrust max load rating of 375#. It is worth noting that although the cylindrical bearing has 29% higher load capacity, in thrust it has only 26% of the capacity of the deep groove single row 6204 bearing.
__________________
Charles Navarro
President, LN Engineering and Bilt Racing Service http://www.LNengineering.com
Home of Nickies Cylinders, IMS Retrofit, and IMS Solution
Knowingly or not, this is missleading and non-sens information. I'm an engineer and worked at at one of the worlds largest bearing mfg. I've reversed engineered the IMSB loads and ALL BEARINGS USED are overkill for the application in regard to load - life.....not surprisingly. 6204 or roller or dual row, all of them have load bearing which is MUCH higher than needed. These bearings fail for other reasons.
Knowingly or not, this is missleading and non-sens information. I'm an engineer and worked at at one of the worlds largest bearing mfg. I've reversed engineered the IMSB loads and ALL BEARINGS USED are overkill for the application in regard to load - life.....not surprisingly. 6204 or roller or dual row, all of them have load bearing which is MUCH higher than needed. These bearings fail for other reasons.
Knowingly or not, this is misleading and nonsense information.
Knowingly or not, this is missleading and non-sens information. I'm an engineer and worked at at one of the worlds largest bearing mfg. I've reversed engineered the IMSB loads and ALL BEARINGS USED are overkill for the application in regard to load - life.....not surprisingly. 6204 or roller or dual row, all of them have load bearing which is MUCH higher than needed. These bearings fail for other reasons.
Actually, I find this information very interesting. The point being made here is that clearly all the load cases for the IMS bearings were not understood in the original design of the motor. Hence the early failures. Some have said the use of a permanently lubricated sealed bearing was a poor choice in the original design. What I took away from Nick's post is that a debate over rating numbers for bearings may be obscuring the load case that causes the failures, or the design feature apart from the rating which may be leading to the failures. Personally, I would like to see a debate on what could in fact be the condition, or the design feature that leads to so many failures.
Some have said the use of a permanently lubricated sealed bearing was a poor choice in the original design
Not so true. The original dual row IMSB had a very low failure rate ( <1%), but they can fail. Probably more due to the original Porsche recommendation of 15,000 mile oil changes. 20 some years later, and with mounds of data/experience, now we know that that was a very bad idea. 3-5K mile oil changes makes failure of a dual row IMSB almost non-existent. It was Porsche's changeover to the weaker (and cheaper) single row IMSB (6204) that led to the class action lawsuit for engine failures and replacement engines. The newer and larger 6305 (corrected - Thanks Charles!) IMSB is very robust and does not fail with proper maintenance (oil changes).
Not so true. The original dual row IMSB had a very low failure rate ( <1%), but they can fail. Probably more due to the original Porsche recommendation of 15,000 mile oil changes. 20 some years later, and with mounds of data/experience, now we know that that was a very bad idea. 3-5K mile oil changes makes failure of a dual row IMSB almost non-existent. It was Porsche's changeover to the weaker (and cheaper) single row IMSB that led to the class action lawsuit for engine failures and replacement engines. The newer and larger 6204 IMSB is very robust and does not fail with proper maintenance (oil changes).
So as a single row 966.2 driver, I had the IMS replaced back in January with the LN "replacement" I think it's called. The IMS that came out with 43,xxx miles on it looked fine sitting on the bench but did not turn freely. So I don't quite understand how the condition of the lubricating oil in the engine could affect the bearing internals unless the permanent seal failed and allowed infiltration into the race. It was my understanding, and maybe this is incorrect, that the bearing was sealed.
06-28-2022, 10:56 PM
