If you can hear a knocking sound from the suspension, then check the following items:

Worn ball joint

Check to see if the upper and lower ball joints in the control arms are worn or require adjustment. 

Check main ball joint nuts to ensure they are tight. 

Check ball joint boots for any damage, replace if nesecary. 

Using grease nipple on ball joint cap add grease. 

Replace if required.

Worn wheel bearings

Check to see if the wheel bearings are worn or damaged. 

Check front wheel bearing nut for tightnes. 

See the service manual on how to check them. 

Replace if necessary.

Worn or damaged shock absorber

The upper and lower bearings in the shock absorber could be worn or damaged. 

Check the springs and the nylon bushes to see if they are damaged and are in good working order.

Check top and bottom mounting bolts.

Replace if necessary. 

 Tie rod ends and steering rack. 

Check both tie rod ends to see if they are damaged or the rubber boots are torn. 

Check inner steering rack ends for play.  

Replace if necessary.

Control arm bushings 

Check upper and lower control arm bushes for damage or excessive wear.       

Check the metal bush inserts installed in the frame for damage or wear.

Check the control arm mounting bolts for tightness. 

Check the frame inserts for damage.

Replace if necessary.