funny you should ask i wasn't sure wether it was a knocking or a clicking noise. i think more a clicking noise. Track rod?? whats that and how expensive is it to fix??
track rod end - steering joint attached to hub assembley.
Constant velocity joint - inside front hub assembley on the end of the driveshaft allowing the rotational action of the drive to be transmitted to the drive flange through an angle equal to the steering movement.
Cv joint is the more costly to replace
Thats what I was goig to say, definitely the cheapest, easiest thing to check, when I did my swivel ball I snapped my lock stop and as a result the tyre was catching on somert when on full lock. Two minutes of a job to check, and 5mins to sort if thats what it is.