It could also be the plastic gear in the gearbox that worn, mine bobbed up and down for ages then gave up the ghost. Fitted a new cable (Not that easy unless you can jack the car very high, its right in the middle of the car) and it still bobs around... Apparatly the gear is £3 but you need to drop the box a little to fit it. Still dont think its that big a job though. To much for me however