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Collection, Preservation and Display of Old Lawn Mowers

4: Removing Collar From Drive Shaft

Figure 4: Holding the release collar whilst tapping the drive shaft free.

The next operation is somewhat controversial: you need to begin working the drive shaft back and forth, applying more penetrating oil as necessary, so that little-by-little, the drive shaft begins to move relative to the release collar. I first tried a 3-legged wheel puller for this operation but found that I had applied so much force without any success that I feared breaking off pieces of the release collar. Figure 4 shows the sprocket retaining nut having been screwed on to the end of the drive shaft to be flush with the threaded end of the shaft. This can then be tapped “sharply” with a hammer to help shock the shaft free of the collar whilst supporting the release collar on the jaws of a vice. It has to be understood here, that there is a significant risk of deforming the threads of the shaft, so some judgment needs to be made as to how hard to strike the shaft & nut. Tapping the shaft and clutch housing in opposing directions with the aid of penetrating oil in this case gradually freed the release collar from the shaft and allowed disassembly of the mating clutch cone surfaces as shown in Figure 5.