A drive shaft, driveshaft is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement between them. How to tell if a drive shaft is bad ? A bad drive shaft can can produce vibration while driving or stationary and at high speeds the vibration is worsened and intensified . Other symptom of a bad driveshaft is the squeaking noise which aggravates when you increase the speed of the car .This often is due to a bad u joint which is connected to the drive shaft .Another symptom of a bad drive shaft is it manifest problem when you turn your vehicle . A joint which moves too much or does not rotate at all can indicate a bad driveshaft. So if your car indicates the above mentioned symptoms then its time to replace your driveshaft. We at cosmo car parts have high quality drive shafts and we will hook you up with the right drive shaft at the best price .