Recently a speedometer on one of my cars started making these weird shrieking sounds that grew louder with speed till the noise was unbearable. The noise resembled a cat being put thru a wringer and the only immediate solution was to disconnect the speedometer cable to preserve my sanity.
These speedometer units are about half a century old and I had a fair idea what would be the problem so I took it apart and serviced it at home. I took pictures as i went along to share here just in case you may have experienced the same problem or if the speedometer cable has snapped inexplicably after a short time of operation. One of the causes of speedometer cable failure is the jamming up of the moving parts which is also the cause of the weird noise.
So here we go. The first step is to remove the speedometer from the car by loosening two flat head screws that hold it in place on the dash. Before you disconnect any wires, flag each with a small piece of paper and some scotch tape. Write on the piece of paper where the wire was connected..e.g. indicator, oil, generator, high beam, instrument light, earth etc.
The tools required are a flat head screwdriver and pointed nose pliers (chooha plas). You would need some cleaning solvent or WD 40, a tiny bit of grease (good quality) and some silicon lubricant spray.
SO here we go. Grab some pop corn and enjoy the show.