Oh yeah the speedo measures rotational velocity via the coupling, the
odometer measures rotations and is directly coupled to the cable.

Al

On Tue, May 4, 2010 at 6:55 PM, Al Knoll <anasasi@gmail.com> wrote:
> The cable spins a plate which magnetically couples to the speedometer
> cup causing a rotational force that is balanced by the return spring.
> The odometer has a pair of reduction gears which drive the set of
> number cogs. �In short they're separate and if the cable is faulty
> generally the speedo bounces or doesn't work at all. �I'd guess it's
> the odometer gear train. �Only a SWAG though.
>
> Al
>
> On Tue, May 4, 2010 at 5:37 PM, miguel pacheco <mundopacheco@gmail.com> wrote:
>> Wow, that is a long way! Throw in a flood in western Tennessee and it
>> gets longer. Trooper ran great! Not one hiccup and I am VERY happy
>> with it!......although, recently, on a trip to Leadville, Co., the
>> odometer (88 Westy 2wd manual) stopped working. Upon inspection, it
>> turned out to be the classic, where the shaft backed out. I put it
>> back in place and using the Tencent method, I installed a 'stop' ahead
>> of the gear so the shaft would not back out again (it simply can't
>> now.) I bench tested it and speedo + odometer work fine, but installed
>> and blowing down the road, the odometer did not work. Pulled it again
>> and checked it and it works fine. The speedo is fine but noisy....the
>> odometer still does not work. Could it be that the cable is the
>> problem? Does the cable spin two different gears, one for the odometer
>> and another for the speedo?
>> Thanks!
>> Miguel
>>
>> I have not failed. I've just found 10,000 ways that won't work.
>> �- Thomas A. Edison
>>
>