>I'm not sure about others but since I have a new speedo and cable I'll
tell
>you about mine. The needle sways/wobbles a small amount and fairly
slowly
>above about 55mph. What I put this down to is the way the odometer
counts.
>On my speedo (series II) the fractions of a mile only turn in discrete
>steps, and it takes about three steps to read 0.1 of a mile. On an open
>piece of road it is possible to watch the needle sway as the odometer
ticks
>on. So I put it down to that.
Anthony,
I think you have a pretty good description when the speedo
jumps, now heres why.
The Smiths/Jaeger speedo has two jewels. I think they are made of
saphire, bit thats not really important.
The speedo needle and disc are held tight in place by the tension of
the jewel in the driven magnet, and the jewel on the end the needle
end. As these jewels wear, or as the thrust in the driven magnet wears,
the speedo will begin to bounce, especially as the driven end moves
in and out due to the odometer load.
The whole assembly can be tightened up with a single screw
adjustment on the inside of the speedo.
The adjustement is pretty sensitive, and I dont have a procedure,
but if you take your time, and adjust little by little "not too tight",
you can test with a drill motor "in lieu of the speedo cable",
untill the action tightens up.
I have resurected 2 speedos that previously jumped around terribly,
so this can be a DIY.
Jarrid Gross
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