It just started making a deep clicking noise more backing up than going forward and a vibration all at varey low speed 0 to 5 miles. thought it was in drive line like a u-joint. my first BMW looked under and no u-joints. A small amount of play in drive line when in nutral but I am not shure how much shoul be there noise is not there all the time. You can not see the middel of drive line with out droping exhaust. Can any one help me out?