ST2 pages
- countershaft sprocket retainer
ST2 pages
- countershaft sprocket retainer
Information on this page last updated 07/18/02.
I have heard many reports of the countershaft sprocket retainer wearing out and allowing the sprocket to work its way off of the countershaft. In March of 1999 the UK Ducati importer issued a recall for this and in June of 1999 Ducati North America sent out a letter announcing this as Recall Campaign I.D. No. 99V-137 for 1998 ST2s VIN WB002137 to VIN WB003736 inclusive. The teeth of the retaining ring may apparently wear out and allow the sprocket to work its way off of the countershaft. This does not appear to be limited to just 1998 models though as I have heard from the owner of a 2000 model with the same problem.
If you are unfamiliar with this retaining clip, take a look at item number 13 in this picture. I have not experienced this problem myself but it seemed serious enough to take some preventative measures. I had read an idea for a backup, or "fail-safe", retainer a while back on one of the mailing lists and applied this to my ST2. There is a threaded hole in the end of the countershaft so just get a bolt that fits these threads (8mmX1.25 thread, 20mm long) and a washer that is larger in diameter than the end of the countershaft. As you can see in the photo I had to file at the washer a bit to provide clearance for the stock retainer bolts. The new bolt and washer are silver in the photo, the stock parts are gold. This all fits under the stock cover just fine, although I had first tried an allen-head bolt and the head was a bit to thick and interfered with the cover.
Note that this backup will prevent the sprocket from coming off of the shaft but it will not prevent the sprocket from moving in towards the engine case. I've heard from two people who had this happen and if not caught quickly it could lead to some case damage. So even with the above-mentioned backup it still pays to take a look at the countershaft whenever you are down there checking the air in the tires or lubing the chain.
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