this cud b the driveshaft.....but dis cud only b 1 reason. u need 2 cheack all bull joints (steering system, suspenshion system) also cheak the power stearing fluid (if fitted). the only way of cheaking witch with drive shaft is 2 take bouth off. i no its a lot of work and effort, but it will save u alot of money if u chang the wrong 1. in the drive shaft u have bearings, these cud be worn causing the knocking. please get back, wud like 2 no the out cum.
indelion
July 2008