Adjusting the gap on the Glendinning Cablemaster can insure more positive retraction, but it can also lead to motor failure by not allowing any slippage between the cable and the retraction wheel if you adjust it too tight and the cord binds on something. My suggestion is to not adjust the reel until everything else has been tried, especially just cleaning the cord. Also, because of the accessibility of the Glendinning reel on most Beavers, adjusting it is a difficult job.
The above statement pertains to Beavers using the Glendinning Cablemaster (cord locker style) and not the coaches the roll the cord onto a large reel.
Gerald