What cause my vehicle to make clunking noise

This is usually caused by a mounting problem and not the shock or strut itself.

Check the components that attach the shock or strut to the vehicle. The mount itself may be enough to cause the shock /strut to move up and down. Another common cause of noise is that the shock or strut mounting may not be tight enough causing the unit to have some slight movement between the bolt and bushing or other attaching parts.