speedo cable broken 280i

[bobs280i]

Hey mates ....i have a broken speedo cable on my 1986 280i (whats it from)???? no wonder it looks like in doing 60 mph sitting in my driveway.

[Wedg1e]

bobs280i said:

Hey mates ....i have a broken speedo cable on my 1986 280i (whats it from)???? no wonder it looks like in doing 60 mph sitting in my driveway.

Errr... if the cable was broken surely the speedo would read zero? Sounds more like a damaged speedo...

The cable is a bit special as the threads on each end weren't common on Brit cars - well not on the same cable anyway.
Most people just post the broken one off to Speedy Cables and a new one turns up about a week later. I had an even more special one made in two pieces and to my dimensions and it was £54 from memory. My car is the only cruise-equipped Wedge on the planet so the cable was made for the speed transducer behind the dashboard.

[bobs280i]

Thanks , well that sucks , yeah its snapped , it must have caught something on the ground ,i will have to make sure the new one is tied tight to the frame....yeah speedo needle is stuck , when i remove the cable hopefully it will drop to zero, where in England is this company who fixed yours .

Thanks Bob

[Wedg1e]

http://www.speedycables.com/

Speedometers usually work by having the cable spin a disc magnet that is a close fit inside a steel cup. The faster the cable turns, the more 'torque' the magnetic field exerts on the cup and the higher the speedo reads. The needle has a return spring and as there's no physical connection between magnet and cup it should be at zero unless the cable is driving it. Could be that the broken cable has somehow twisted the magnet so it's jammed the cup and is holding the needle up.