For over the last ten years, LN Engineering has been supplying replacement IMS bearings to the aftermarket to address known issues brought to light by the Eisen class action lawsuit.
The single row bearing utilized from model year 2000 through 2005 are the weakest of bearings. If you haven't replaced your bearing yet, now is time to consider a replacement.

Fact 1: IMS bearings have service intervals.

However, there are many, over 35,000 vehicles, with IMS bearings that were replaced many years ago that may need replacement. The IMS Retrofit, unlike the IMS Solution, is designed to be a service item. Whether you are the owner of a vehicle already Retrofitted or looking to buy one, there are a few things you should know. 

The Classic Single Row IMS Retrofit has a 4 year or 50,000 mile service interval, whichever comes first.

Years later, the Single Row Pro was released that allowed a dual row bearing to be fitted with a longer 6 year or 75,000 mile interval.
I already have LN Engineering's kit installed in my car. How will I know if my IMS Retrofit™ bearing needs replacement?
Use our Online IMS Check. Get info about your installed IMS Retrofit ™ or check if the car you're about to purchase has it. Use either IMS serial number or your car's VIN number to find your  Date of registration (up to 30 days from installation), Bearing type, Mileage at the time of installation, your IMS Retrofit™ serial number and Name of the shop / installer.
Fact 2: The IMS Solution is the only IMS replacement with no moving parts to wear or fail and is designed for the life of the engine.

The IMS Solution is a permanent fix, backdating the engine to an oil fed plain bearing, like an air-cooled 911's engine.
Fact 3: The M96 engine is wet sump

With the grease seal removed off the IMS bearing, it is submerged in oil and a ceramic hybrid bearing only needs 1cc of oil per minute for proper lubrication.
This is not to be confused with an external oil feed (or delivery system) like Direct Oil Feed® / DOF®, which supplies oil to a ball bearing that is already submerged in oil, or a supposedly permanent roller bearing. 

Fact 3: Some claim roller bearings being 5 to 12 times stronger. But stronger than what?

Here are the facts on bearing load ratings. Look them up yourself in any bearing catalog.
  • A deep groove ball bearing as currently used in the IMS Retrofit can take up to 50% of the dynamic load in thrust.
  • A traditional cylindrical roller bearing with thrust control can only take up to 10% of the dynamic load in thrust in one direction!
  • The factory single row 6204 bearing a dynamic load capacity of 2900# with thrust max load rating of 1450#. The factory chose a single row ceramic hybrid for their bearing replacement.
  • The custom dual row ceramic hybrid bearings used in both the Single Row Pro and Classic Dual Row IMS Retrofit has a dynamic load capacity of 4000# w/ Thrust or 2000#.
  • The NJ or NU204 cylindrical bearing used in most roller bearing kits have a dynamic load capacity of 3750# with thrust max load rating of 375#
  • The NUP204E cylindrical roller bearing used in the RND RS Roller kit has a dynamic load capacity of 5800# with max thrust load rating of 580# in both fore and aft, all handled internally by the bearing.
Fact 4: The 06-08 IMS bearing is the strongest bearing used by the factory.

Model year 2006 to 2008 vehicles should not have the IMS bearing removed and replaced unless complete engine disassembly is carried out. Invasive boring procedures to the case will most certainly lead to catastrophic engine failure or collateral damage. Learn more about what owners of these model years should do at
be fitted with a longer 6 year or 75,000 mile interval.
LN is offering a mail in rebate for existing IMS Retrofit users when upgrading to the IMS Solution or another IMS Retrofit.
Visit for details, terms and conditions.
Used bearings should never be reinstalled.

Pulling on the inner race transfers the forced through the balls or rollers to the outer race. This loading of the bearing causes brinnelling of the bearing, with microscopic dents on the races, that will lead to bearing failure.
After you have replaced your IMS bearing, the original should be sent back to LN Engineering as part of the warranty registration process.
Sadly, there are some willing to take advantage of owners lack of knowledge when it comes to the internals of their M96 engine. These eBay sellers are selling used original factory bearings, as well as one seller selling used LN bearings that have been clearly media blasted, with photos showing contamination on and in the bearings. Installing any of these used bearings will lead to catastrophic engine failure. It's also worth noting the date codes on the LN bearings indicate these bearings were long overdue for service, for example C3 referring to March 2013.
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