Prolly find the drive unit in the wheel isnt the right one causing the cable to bend at a very shap angle , or the drive is worn inside lack of grease , had it once a 350 goose was the wrong drive unit so didnt sit correctly in the fork slot , and put undue stress on the cable and drive nackerd both in 3 months , new set off ebay and was perfect after.Other than that check the routing try not to have sharp bends kinks in the cable .