How sturdy and dependable are the universal joints in these cars? I know that mine is full of black sticky grease and I don't feel significant backlash. I suppose that I could convert it to a more modern part, but I don't know if it will still fit inside the housing. So, the question is, should I convert it or leave well enough alone? I do have plenty to do already. Remember I will be going through the big rally race, Peking to Paris and II don't want to break down in Mongolia..