The Cable runs both. The Odometer is run by the gears.
Looking at the face of the Spedometer, there is one plastic
gear shaft, that goes to the right, and drives another gear shaft faces forward that turns the Odometer numbers.
Also as the spedo cable it turning, it spins a magnet in a cup which makes the needle move to show how fast you are going.
This is what I have figured out, having taken one apart.
I installed a new 6 digit spedo head in my 86 last year.
I wanted it to have the correct mileage.
There is a set of 6 Cogs on a shaft under the # wheels.
Remove the clip on the end of the shaft, slide it out and the Cogs come off.
Turn the # wheels where you want them.
Slide the shaft in and replace ea Cog as you slide it in.
Replace the clip.
I have had Mercedes Spedo`s from the Diesels of the 80`s
taken apart, and both are made the same way.
To remove the Needle, 2 spoons on 2 sides, pry up it should com off.
On the back side are 2 screws, and the Face comes off.
You might be better off picking up a Instrument Panel off
a wreck in a PNP yard and remove the Spedo Cluster and then change the Mileage if your gear`s are bad.
Forget buying a Inst Panel off E-Bay, they think they are gold plated.
Goat
