IMS Bearing Replacements for 2000 and 2001 Model Year Porsche Boxster and 911 Engines
Starting with model year 2000 and ending with 2001 models, Porsche Boxster and 911 engines were fitted with both dual row and single row intermediate shaft bearings. Although the dual row bearing has a much lower incidence of failure than the single row bearing used by Porsche, both bearings need to be replaced as part of regular scheduled maintenance. As any 2000 or 2001 model year engine could actually have the weaker single row IMS bearing, we recommend assuming your engine has this weaker bearing and have it replaced as soon as possible. Failure rates for engines with their original Porsche IMS bearing will only increase as these engines get older. But before ordering a replacement IMS bearing to upgrade your Porsche 986 or 996 engine, it is important to identify which intermediate shaft bearing your engine actually has.
What IMS bearing does my engine have?
From 1997 to 1999, Porsche use a dual row intermediate shaft bearing which has
proven to be as robust as the larger single row used from 2006 through 2008
model years. The Eisen vs Porsche Class Action Lawsuit filed against Porsche
over IMS failures revealed the factory Dual Row was much stronger than the
Single Row used from 2000-2005. According to information published about the
Eisen IMS Class Action Lawsuit, the single row IMS bearing used in 2000
through 2005 model years is reported to have an 8% failure rate, versus less
than 1% with the dual row IMS bearing which has twice the load capacity of the
single row bearing used by Porsche.
By far, the single row ball-bearing used starting in model year 2000 through 2005 are the most problematic. Although some claim the problem with the ims bearing is due to lubrication alone, with half the load capacity, it is clear to see that the reduced load capacity of the single row IMS bearing is a significant contributing factor to the increased number of failures and that oiling alone is not the cause or solution to IMS issues. If oiling was the main reason for failures, we would have expected an equal rate of failure for all factory IMS bearings, where the early dual and late MY06-08 bearings had a very low failure rate, approx 1%m under warranty.
Starting in 2000, Porsche began phasing out the dual row bearing and went to a smaller single row, with significantly less load capacity. From 2002 through 2005, all engines used this smaller intermediate shaft bearing until they went to the larger, third revision for the 2006 model year, which increased the load capacity back to what the original dual row bearing could support. The larger model year 2006 and later bearing also increased the diameter, which increased the bearing and ball speed, further improving the bearing. However, this change has not been enough to resolve the IMS failure issues completely.
It is also important to note that if the engine has been replaced and is not original to the car, the engine will have whatever IMS what currently being used for the model year in which the engine was manufactured. Typically replacement engines will have an AT, X, or Y in the engine serial number, which is located on the side of the sump.
An engine fitted with a factory single row IMS bearing can be identified by measuring the original IMS flange dish depth. A single row IMS measures 19.27 mm where a dual row measures 13.34mm.
Where can I learn more about the IMS Bearing in my Porsche Boxster or 911 engine?
LN Engineering's intermediate shaft (IMS) bearing FAQ has everything you need to know about your Porsche M96 engine's original dual or single row IMS bearing. Additional information about LN Engineering's IMS bearing solutions can be found on the IMS Retrofit or IMS Solution website.
SKU: 106-08.40IMS Solution for Dual Row IMS MY97-01$1,899.00
SKU: 106-08.IMSRORINGSIMS Retrofit O-Ring Kit$19.95
SKU: 106-08.INSTALLKITM96/M97 Camshaft Plug and Tensioner Seal Set
SKU: 107-10Advanced Technical Support (ATS)$170.00
SKU: IMS-TOOL-BUNDLEIMS Bearing Installation Tools Bundle
As low as: $516.60