Are you new to the M96 engine and the IMS Retrofit?
There are several versions of the IMS used from 1997 through 2008. LN Engineering currently offers a dual row IMS Retrofit as well as a single row IMS Retrofit, where the engine does not have to be disassembled to replace the factory sealed ball-bearing.
The LN Engineering IMS Retrofit uses a custom open (no grease seal) ceramic hybrid bearing (US or Japan sourced components). Typically, replacement of the IMS bearing takes 10+ hours when also replacing the clutch assembly at the same time. All MY97-99 vehicles with their original engines will require a dual row Retrofit™ kit, identified by a wider dual row ball-bearing and narrow IMS flange.
MY00-01 vehicles may need either a dual row or single row Retrofit™ kit, so you must inspect the flange and compare to the photos of the dual row and single row IMS shown below to determine which kit is needed.
MY02-05 will need a single row Retrofit™ kit, identified by a narrower single row ball-bearing and wider IMS flange.
Some late model year 2005 engines were fitted with a larger bearing that is not serviceable without a complete teardown of the engine. All MY06 through MY08 engines will have the larger single row ball-bearing identified by the larger 22mm nut. These cannot be serviced without complete disassembly of the engine due to the intermediate shaft being redesigned! LN Engineering does offer a MY06-08 IMS Retrofit kit for the larger bearing found on model year 2006 through 2008 M97 engines, but engine disassembly is required for installation.
LN Engineering also offers an IMS Upgrade service where you send in your intermediate shaft and it is upgraded to a triple row bearing (with exception of MY06-08). Additionally, the main drive sprocket is pinned to prevent slippage of the drive gear, which is a known problem area.
Additionally, if the engine is not original to the car, for example a car that might have a replacement engine, it will have whatever type bearing was currently in production for the model year in which the engine was built. One easy sign that you have a remanufactured factory engine that has been replaced is if there is an X in the engine number located on the lower edge of the engine’s sump.
The IMS Retrofit and IMS Solution procedures are intended for PREVENTATIVE and not REACTIVE measures only and should be considered a maintenance item, like a timing belt on many modern engines. By no means should an IMS Retrofit procedure be carried out if the original bearing has started to fail as the intermediate shaft will be damaged by such failure. Once your original bearing has failed it is too late. If the IMS bearing needs to be cut out of the IMS bearing tube (shaft) to remove it, by no means can a new bearing be installed! The engine will have to be disassembled and intermediate shaft replaced.
Considering all three revisions of the IMS found in the M96 and M97 are known to fail, LN Engineering knows the original use of a ball-bearing was a manufacturing constraint and a poor choice. That said, even the addition of a ceramic hybrid ball-bearing with its superiority over conventional ball bearings does not eliminate completely the chance of failure. With zero failures of their dual row IMS Retrofit, triple bearing IMS Upgrade, or even with their upgraded ceramic hybrid bearings used in the model year 2006 through 2008 intermediate shafts, LN Engineering has almost a perfect track record. Knowing the single row bearing is undersized for this application, LN Engineering recommends replacement every 4 years or 50,000 miles.
Fast forward to 2009, Porsche’s newest lineup of Boxster, Cayman, and 911 models feature their newest 9A1 engine, which no longer utilize an intermediate shaft to drive the camshafts, but rather drive them directly off the crankshaft.
Recommended Service Intervals:
The Classic Single Row IMS Retrofit has a 4yr or 50,000 mile service interval. Replacement is recommended at time of clutch service and upgrading to the new Single Row Pro IMS Retrofit is recommended.
The Dual Row IMS Retrofit and new Single Row Pro IMS Retrofit both have a 6yr or 75,000 mile service interval.