If you go far enough back in this forum, ie about 3-4 years you will find loads of info on this. If your car has a Quaife diff, then that will be the root of the problem. Many were noisy, clunky and with loads of backlash making the car difficult and annoying to drive. Caterham eventualy started fitting the BMW diff and drive train and that transformed the cars from hard core racers to sophisticated tourers. I changed mine from Quaife to BMW, if I hadnt done that, I would not be a Caterham owner now! Suggest you study the history. peter