Leyland P76 Owners 2003

Technical problem

Speedo Fixes

Articles supplied by Jilden

Hold on to any old speedos: they have a valuable gear in them!
Recent failure of the odometer on my wifeís P76 led me to find that the plastic gear that drives at right angles off the input shaft gear was WORN OUT!
My supply of spare Metric V8 tripmeter speedos was looking somewhat grim, so I investigated the removal of this nasty little bit.
By removing a little bit of cast metal from beside the gear , where the centre shaft sticks out of the case, and a careful scrape with a sharp chisel, I could make the hole big enough to remove the gear in one piece.
Then I removed its shaft carefully with a pair of pliers and the worn gear came out.
The driving gear is machined steel, and shows no wear.
Dismembering an old 6 cylinder speedo, I found this gear to be unworn, and identical.
Being as new, it took a little more work to get it out without damaging it, and it was soon installed in the V8 speedo. A little oil and grease and it was back to normal.
Previously, I have fixed intermittent odometers by fixing slipping bits on the actual odometer spindle.
Especially in hot weather, the grey plastic wheel adjacent to the units counter comes loose on its shaft.
To fix this problem involves carefully sliding out the shaft JUST ENOUGH to expose the point on which this wheel sits. Then the shaft is burred with side cutting pliers at this exact spot, and forced back in (carefully!) until the burrs lock into the grey plastic wheel.
The small gear that drives this shaft sometimes slips too, so a small amount of burring under this does not go astray. Some speedos have a small brass collar on the shaft which prevents it being pulled out; it has to be cut off with pliers and discarded: itís not really needed.
The fun part of the above operation is getting the numbers and relay sprockets to line up properly again before final assembly.
You can invent any required odometer reading here, but you must have keen eyesight and lots of patience to get the bits lined up exactly right afterwards!
Study the mechanism well first, or better still, have a spare speedo nearby to compare.
Your patience is rewarded with a zero-zero-zero reading for that special project car that you have just completed. Happy fiddling!
Jilden Reichardt

Last updated
Dec, 2005
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