Odometer not counting mileage

I noticed yesterday that my miles weren't clocking up. I had speed showing correctly on the needle but. I miles. 
I followed a guide previously mentioned and have stripped out the mileage block. 

I can freely move the metal gear with my fingers on the far right in the top numbers. Is this correct? 

If I add a drill to the drive and spin it up the white worm screw turns and in turn this turns the red cog, but that's about where it ends. I can't seem to make the miles clock up. 

Any ideas?

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Should say 'I had speed showing correctly but no miles"

FIXED!
I've superglued the metal cog back on the shaft that runs through the centre and now all working(When spun up on the drill). 
Just got to our it back in the car now.