The crankshaft thrust washer was specified for 1966 and later BSA twins, which coincided with the revised timing-side crankshaft bush and the introduction of the drive-side roller bearing. We are now offering the Kibblewhite version of the 68-0685 thrust washer.
The thrust washer is precision manufactured to exacting specifications by Kibblewhite in the US. The proprietary bearing bronze is used for increased wear resistance compared to the original material. The washer measures 1.690″ ID, 2.115″ OD, 1.900″ across the locating flats, and is .065″ thick. There no slots cut into the face of the washer.
From 1966 onward, BSA machined the crank cases to allow for the wider crankshaft that was introduced to accommodate the drive-side roller bearing, which offered increased radial load capacity over the deep groove ball bearing previously fitted. The thrust washer is in place on the timing-side case half to center the crankshaft and protect the crank case.
The thrust washer is placed in the machined cutout on the timing-side case half over the crankshaft bush and is retained with a light interference fit and by the crankshaft, once located in the left crankcase half.