How to repair knocking noise at back specially passing in the rough road

How to repair knocking noise at the back specially passing in the rough road.

 

Model:Hyundai Matrix

Year Model: 2009

Fuel: Gasoline

Displacement: 1600cc

Subject: Rear knocking noise at the back specially passing in the rough road.

1) Condition

1. Rear knocking noise seems like loosen bolt underneath.

2) Cause

1. The problem cause from the rear shock absorber.

3) Diagnosis

1. Check the car by road testing to confirm the owners problem = Positive noise 
2. Lift up the car for visually check up.
3. Try to retighten all bolt. Ok all bolt tight.
4. check the wheel bearing by means of holding the tire upper and lower portion.= to check the clearance. OK
5. pull out rear shock absorber.
   =Positive clearance from the rear shock.

4) Parts Replace         

1. Rear Shock Absorber.

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