Suspect Tailshaft Problem
 

My car started making a new noise tonight. suspected tailshaft because its changing with the speed of the car and when the car is stopped the noise disappears and does it in reverse and forward and makes a clunk around corners sometimes.
any ideas ?

how much would a new or repair tailshaft cost ?
im in perth WA australia

should the tailshaft move when the car is off and in park both ways clockwise and anticlockwise. or is this not normal. wheels are on the ground and it turns both ways ?