1980 K100 Cabover Project/daily runner

Get a new cable or buy an electronic "transducer" and install an electronic speedo

 

We called those speedometer ratio adapters. They normally had the ratio stamped or engraved on them so they could just be replaced with the same. Shops used to have kits full of gears, drive ends and such to make anything needed. A tool to hook up to the transmission that would tell want ratio is needed. A spool of housing and cable. Ends for the housing and a tool to square the cable end. That would be hard to find today. If you are liking all those new gauges I would just go electronic.

 

Truck wrecking yard or any parts house would have new ones

 

It's still gear driven from your tranny, it just converts it to an electric signal. Most like ohms, like a fuel tank sending unit but I could be wrong.

 

They were not KW's but we used to put a tone wheel in for the pickup, replaces the gear. Machine shop up the street would thread the housing for the sensor at a fair price. We were changing IHC's from a tone wheel pick up off the RF hub to transmission driven. We tapped into the original wiring but you would have to run some. I thank a good two wire speaker harness would work. Run it to the speedo and wire it all up.
I said thank because I have never done that. I doubt there is any need for shielded wire like the few hundred feet I drug home today. I never saw it coming but could see it in the mirror.
The thing DD mentioned is interesting but I have never seen one. I will take that back but do not remember where and have no idea about calibration.
Like 51.50 said wrecking yard, or a trans builder. They have been selling them for scrap many years but might have some parts sitting around.
Not in the subject but check out your wiring harness up by the steering box, nothing wearing thin?

 

Like lili and smoking said I am sure there is some net stuff out there today.
This is the way we calibrated them. The speedometer head had dip switches in the back for calibration.
We knew the trucks would run 68 MPH at 2100, wide open. With the driveshaft off the transmission we ran them in high at full throttle. Flipped the switches to get 68 MPH.
That is a lot easier to do when it is company trucks and it cost you nothing if you smoke something. Ask who you buy your equipment from.