bonesbradly told me that if its popping out of reverse then yes sadly they gearbox is on the way out, but change the oil in it for some fully synthetic stuff and it will last a good 30k+. ive recently changed mine and it has somewhat sorted the problem, gearbox not so stiff from cold and doesnt pop out of reverse so much. if its only just started doing it change ur gearbox oil quick and u wont have to fork out to much $$$ so quickly!