type 9 cable rotation

[mgglep]

Hi all bizarre question but does anyone know how many times the Speedo cable rotates per revolution of the wheels on a Ford type 9 box can't test it myself as I haven't got a cable on my box
Cheers

[twinturbo]

depends on speedo drive gear as there are a few different applications.

TT

[alga]

In general most speedos are calibrated for 1000 revolutions per mile. The Sierra tyre size is 185/60R14, which gives 887 revs per mile, which means 1.127 revs of the cable per wheel rev.

When I switched from mechanical speedo to digital, I used a Hall speedo sensor that sends 8 pulses per revolution in place of a cable. I calibrated the speedo for 5000 pulses per km (=8046 pulses per mile) and it is dead on.