Cable Stretch
It is the slight increase in the length of the stranded inner wire, caused during the first operating hours by the strands bedding in and later on by fatigue. The result is that the pretension left at idle is lost and part of the travel is wasted on slack. Stretch spoils the calibration; it is one of the typical reasons for re-teaching on the GS740-3P.
A new cable goes through a short bedding-in period during its first loadings as the strands in the braid settle against each other. In this phase the stretch is relatively fast and it is normal. That is why it is a good habit to check the tension once more after the first operating hours following installation.
The symptoms of stretch are clear:
- Over the first part of the potentiometer the speed does not change, then it rises abruptly.
- At full throttle the engine no longer reaches as high a speed as before.
- Idle stays the same while there is a noticeable loss at the top end.
The order of the fix is this: first re-establish the pretension with the adjusting nut or the clamp at the cable connection, then repeat the calibration. On the GS740-3P this means erasing the memory via the blue wire and teaching the upper limit again. Teaching done without correcting the tension will drift again before long.
Context in which this term is used: Electronic speed and throttle control on a diesel engine