Speedometer Clutch Repair

I have intermittent faults with my speedometer, as I may have mentioned once or twice - either sticks at zero or runs around to full scale and stays there. This is caused by the clutch slipping and leaving the camshaft either with the commander pinion engaged, driving the needle right round, or failing to engage the pinion at all, leaving the needle at zero. As with many speedo failures, this is caused by over lubrication.

The first step is to pull the speedo out. Fed up with trying to maneuvre my hands under the top yoke, I removed the headlamp first:

This means that you can remove the cable, the speedo lamp and the little M6 nuts securing the speedo into the yoke very easily.

This post is not going to be a speedo rebuild tutorial. There is a lot of that already on this blog, and more in my forthcoming book. No, this post is just to record the rebuild of the speedo clutch; this first step is to strip the speedo down to the movement and then take the movement apart for cleaning and inspection.

This is the clutch, disassembled with the parts in the correct sequence. I have cleaned them with methylated spirit and a brush.

They are lying on a sheet of white paper - very useful for cleaning wheels!