[Vwdiesel] Funky Odo

[Sandy Cameron]

Most speedos are a rotating magnet inside  an aluminum drum attached to the
pointer.

Without getting into a nitpicking argument about eddy currents, etc,  It
works by the magnet "dragging" the drum against  the tension of a spiral
return spring.

They are calibrated in 2 ways, adjusting the tension of the spring, , and a
magnetic "shunt" across the gap in the magnet .
The magnetic "shunt" across the gap can be moved to shunt more or less of
the flux, varying the pull or drag the magnet exerts on the drum.

I would suspect one would affect the low end reading, and the other, the
high end.

Do not know which does what.

Sandy