Speedometer problems

And it can do this if the new cable core's square end does not actually engage the socket in the speedo, but just rides on the surface of the socket; it jumps around and engages the speedo erratically. Sometimes, you have to pull the core out a bit at the speedo end, rotate it to perfectly align with the square socket hole, and then insert it into the speedo to get proper engagement. It may work better to connect the speedo end first, and then the trans end.

They can be fussy, 'specially if not the perfect length in the core.