Direct Oil Feed

Oiling is just one part of the problem. The solution is simple. Eliminating the grease seal opens up the bearing to the oil located in the “integrated dry sump,” aka wet sump where all the oil is housed.

As supplied by Porsche, the intermediate shaft uses a sealed ball bearing. The original bearing was grease filled, considered a “permanent” lubricant. However, the original bearings and seals used are rated only to 250F and over time, the seals become hard, allowing the grease under normal operation to be “washed” out of the bearing during operation.

As the intermediate shaft itself is completely submerged at times, the shaft will actually fill up with engine oil. With long drain intervals, contaminants in the oil find their way into the bearings and intermediate shaft. These worn out seals do allow oil in but they also limit the exchange of fresh oil in and out of the intermediate shaft.

Once the bearing begins to wear, the seal will actually fail completely, allowing for oil to wash out the permanent grease but not allowing for fresh oil to exchange in and out of the bearing during operation. It is at this point that you can begin to find debris in the filter from the seal and from the bearing itself.

The IMS Retrofit uses an open bearing (no grease seal), allow engine oil to freely enter and exit the bearing.

The ceramic hybrid bearing used in all IMS Retrofit kits require minimal oiling, far exceeded by oil in the engine’s “integrated dry sump.”

The IMS tube itself will end up storing a sizable amount of oil that will centrifugally be fed to the bearing during operation. This is another reason why frequent oil changes are a must – as this oil gets trapped and is one of the sources for lubrication of the new bearing!

Forced oiling of the ball bearing does not provide any benefit as the bearing does not require or benefit from additional oil. Lubrication alone is not the problem.

“Rolling element bearings depend on the continuous presence of a very thin – millionths of an inch – elastohydrodynamic film of lubricant between rolling elements and raceways, and between the cage, rings and rolling elements. Lubricant-related failures can be avoided by selecting a grease or oil that generates a sufficient film to keep bearing elements separated. A good lubricant also provides good boundary lubrication. Lubricant failures can be detected by the presence of discolored (blue/brown) raceways and rolling elements. Excessive wear on rolling elements, rings and cages follows, resulting in overheating and subsequent catastrophic failure.” –

Some claim without forced oiling of the ball bearing there is inadequate lubrication. Unfortunately, there is no evidence of this with thousands of stock or ceramic hybrid replacement bearings we have inspected. If oil alone was the problem, we would expect failure percentages from the Eisen Class Action Lawsuit to be the same for single and dual row IMS bearings, which is clearly not the case.

Furthermore, the bearing operates submerged in oil or partially submerged in normal operation, for example at idle, when bearing load is highest and need for lubrication is greatest. In fact, it’s possible to over-lubricate a bearing, which causes the balls to slide rather than to roll.

“Too much oil or grease in a bearing or its housing causes an effect called churning resulting in a sharp temperature rise and often premature lubricant and/or bearing failure.

Circulating oil, however, should not be used in high-speed applications, such as machines tool spindles, because of unacceptable friction losses as the lubricant moves through the bearing. In these applications, only a small amount of oil is needed, and a spray-mist system is generally preferred.”  –

For those choosing to retain the original conventional ball bearing, it has been known for years that simply removing the grease seal will promote improved bearing life along with use of an oil with higher viscosity or higher film strength.

The LN Engineering IMS Retrofit kit should not be used with any forced oiling products for which they were not designed for. 

Another issue that forced oiling of a ball bearing does not solve is over-loading of the ball bearing. The single row ball bearing used starting in 2000 through 2005 was replaced with a larger bearing in 2006 with double the load capacity, restoring the original load capacity the dual row bearing first used in the M96 engine. Insufficient load capacity leading to wear and fatigue is the primary problem with the single row bearing used in 2000 through 2005, not lubrication!  It is for this same reason that the class action lawsuit settlement regarding the IMS only covers vehicles with the single row bearing as found in 2000 through 2005 model year vehicles!

The IMS Solution and Single Row Pro IMS Retrofit both provide increased load capacity over the conventional single row bearing, but the IMS Solution eliminates the problematic ball bearing by using a simple plain bearing that is pressure fed oil. Orifice size as well as oil source for lubrication of the IMS Solution has been engineered to ensure optimal operation while not causing side-effects from pressure losses (leading to lifter and variocam problems), oil foaming, and crankcase windage that flood oil feeding a ball bearing causes.