Generally speaking, the function of driveshaft is to transmit the power produced by the engine to some part as it required. Specifically, for front wheel-drive, the power is transmitted to the front. Similarly, the rear for rear wheel-drive; for four wheel-drive, they have two drive shafts and send power to the front and rear. For your reminder, if you change the height of your BMW car, there is a high possibility that the driveshaft gets damaged. What's more, once you change your driveshaft, some related parts like U-joints, should be checked and lubricated as well. Here are some symptoms showing that your driveshaft may goes wrong: if you hear a clunking noise when you accelerate of shift between drive and reverse; if you feel a vibration when you are driving; if you hear a squeaking noise when you drive your BMW, you are supposed to check it immediately. Once you decide to change your driveshaft, we are glad to offer you all BMW genuine OEM driveshaft with a discounted price.