ITEM: Flywheel Nuts AVAILABILITY: In stock APPLICATION: See below PRICE: $45 (Qty.2) PURCHASE: Click Contact button The stock flywheel retaining nut has shown a weakness in that it loosens up even when properly torqued and Loktited.  This problem is frequent enough that Ducati has issued a service bulletin concerning the stock nut.  Very often this has caused severe damage to the crankshaft and rather quickly causes irreparable damage to the splines of the crankshaft.  If the engine is using an aluminum flywheel (in place of the stock steel unit), only the flywheel will be damaged.  The exception to this are the aluminum flywheels which have a steel center.  This kind of flywheel will damage the crankshaft just like the stock steel flywheel. The stock nut is not "self locking" as it may appear to be.  As a test, we purchased several of these nuts from two separate dealers.  Without exception, every new unused nut could be threaded onto crankshafts (more than one crankshaft was used) without any resistance.  Further inspection revealed that the threads of these brand new nuts are actually oversized.  Checking the threads with a calibrated thread gauge showed that at least 25% of the thread depth was oversize.  This is the primary reason these nuts come loose. Our solution to this problem is to use two jam nuts in place of one large flange nut.  This is the same method used on Ducati engines produced in the early 1990's.  Most important is the fact that this method worked and it worked very well.  We selected a medium alloy steel 4130.  We heat-treat it which makes it stronger, tougher and more durable.  We machine it ourselves so we can control the thread-size more precisely.  Whether your Ducati has the stock or an aftermarket flywheel, these nuts are a very worthwhile investment. Fits: M750, M900, 750SS, 900SS, 900FE, 748, 996, ST2, ST4   (Ducati Engines with the 3-Phase charging system) If you have any questions as to your application, please call us at  408-945-0911. Flywheel Retaining Nuts ($45 -- sold only in pairs)