Simple job turned nasty
Customer wants a digital speedo and has supplied a unit with a sensor device that replaces the speedo cable and screws onto the speedo drive take-off at the gearbox. Removing a Mini's speedo cable is not fun at the best of times, but after removing heater hoses and the bottom radiator hose I could just about fit my giant mitt down behind the engine into the greasetrap that accumulates around the speedo drive to painfully undo the knurled nut on the cable. The cable then came out, but the end was all twisted, frayed and broken off (no wonder his speedo wasn't working) - the short length of square shaft was still in the drive gear and stuck good 'n proper
Of course that meant the drive gear needed to come out, so after about another hour of more pain with blood dripping from torn flesh, the 7/16" bolt was removed and the drive gear eventually freed. The broken cable was well and truly stuck in place, but eventually removed. Then to my delight I notice the square shaft on the digital sensor seemed much smaller than the end of the old cable I'd just removed - and when test fitted into the drive gear, it was so loose that it would spin inside the square housing. Measurements showed the old cable to be about 3.15mm square, the new device was 2.5mm

That meant modifying the drive gear's square housing to allow it to turn the smaller square shaft. In a way I'm glad I pulled the drive gear out of the gearbox when I did, because if I'd just fitted the new speedo sensor in situ, I'd never have picked up the fact that it was too small a diameter to be turned by the drive gear. So ...... 4-hours later and there's no light left to wire it up

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Curly
'64 Cooper 'S' (Group Nb spec)
'67 Mini Marcos GT
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