The discussion with epj3 about his differential noise has prompted me to ask this question (which I have actually been wondering about since I got my E30).
Why do our cars have such complicated driveshafts with the flex disk and center support bearing? I don't quite understand why this design is necessary - most vehicles that use center support bearings need them because they have very long and heavy driveshafts connected to a floating rear axle. Our differentials are fixed to the rear subframe, and the driveshaft in a 3 series is by no means a long driveshaft. So, why couldn't they just have used a u-joint at the tranny output shaft, a single piece driveshaft, and a u-joint at the pinion of the differential? This would be a much simpler design with less parts to wear out.
Anyone have any answers? [???1]
Why do our cars have such complicated driveshafts with the flex disk and center support bearing? I don't quite understand why this design is necessary - most vehicles that use center support bearings need them because they have very long and heavy driveshafts connected to a floating rear axle. Our differentials are fixed to the rear subframe, and the driveshaft in a 3 series is by no means a long driveshaft. So, why couldn't they just have used a u-joint at the tranny output shaft, a single piece driveshaft, and a u-joint at the pinion of the differential? This would be a much simpler design with less parts to wear out.
Anyone have any answers? [???1]
![[;)]](/images/smilies/wink.png "Wink [;)]")