Recently I’d noticed clunking, almost reminiscent of piston slap when putting mye engine into gear and running at low revs. My initial thought was that there may have been some J-Type gearbox damage from my old mal-aligned stub shaft. The old stub shaft had suffered a woodruff key and keyway failure resulting in the shaft running un-true and causing an elliptical wear pattern at the join between both halves of the assembly.

Using a long metal bar as an engine ‘stethoscope’, it seemed the gearbox was OK, but that the sound was almost like loose flywheel bolts or the flywheel starter ring gear brushing the starter motor. The only way to truly diagnose was to remove the gearbox and investigate.

It is definitely easier to remove the gearbox from the engine than the engine from the gearbox but removing the bell housing and subsequent starter motor removal almost reduced me to tears of frustration. In the end, to access the two starter motor bolts, I had to remove the oil filter and reach through from the front of the engine, using a mole wrench to hold the bolt on the other side in the absence of a spare pair of hands.

What became clear is the re-machined stub shaft had developed around a degree of rotational play due to a less than perfect fit between the woodruff key and keyway between the two halves of the stub shaft assembly.

At this point I lost faith in the re-machined stub shaft given that it had lasted less than a season.

I put my ear to the ground, posted in a Freeman Facebook group and managed to track a second hand one down (something I’d completely failed to achieve a year before), thanks to the engineer and mechanic, Trevor Orman.

I now need to re-assemble and will update this post to let you know how I got on.