Signs that your car’s suspension is bad (5 common Symptoms)

In this brief article we are going to discuss the signs that your car’s suspension is bad, and how to troubleshoot these signs.

What are the signs that tell you your car’s suspension is bad?

If your car’s suspension is bad it can cause a variety of symptoms  either as sounds or in the way the car responds to steering inputs. The most commonly occurring signs of a bad suspension are:

  • Clunking in the front/rear suspension
  • Knocking Creaking when turning the steering
  • Suspension that feels Bouncy and Squeaky
  • Knocking noises while normal driving
  • Poor handling response
  • Suspension warning messages

How do you Troubleshoot the signs of a bad suspension?

Clunking in the front/rear suspension

  • In most passenger vehicles that have an anti-roll bar fitted, a clunk generally is a sign that points to an issue in either:
    • The Anti-roll bar bushes and linkages or
    • The Shock absorber strut
  • While driving, if the noise increases while going over a rough road, there is a higher probability of the issue being related to the Anti-roll bar (ARB) links than the strut
  • The reasoning for this is that the anti roll bar works only under roll. On smoother surfaces the suspension roll is not so much; the ARB rather just hinges without much stress to the ARB linkages. Hence, the ARB is less noisy when going over a smooth road.
  • A simple way to diagnose the ARB linkages is to hold each link and shake it back and forth by applying force. Observe for movement or noise at each bushing position or ball-joint location.
  • To check the ARB subframe mounts, you could also use a pry bar for a better leverage and accessibility
  • The 2 sources of ‘Clunk’ noises within the Anti Roll bar assembly are:
    • Anti roll bar Subframe mounting, and
    • Anti-roll bar End link ball-joint
  • The Anti-Roll bar (ARB) bushings are the isolators between the ARB and the vehicle’s chassis. The bushings are generally of ‘D’ shape. Their function is also to ‘secure’ the ARB in place and restrict excessive movement allowing proper ARB torsion.
  • The ARB is under torsional loads while the car is undergoing “Roll” motion either during cornering or Rough Roads. 
  • On Rough roads or during cornering maneuvers, when the ARB articulates, the mounting bushes also share part of the road loads.
  • If the rubber within the Bushings has either aged, hardened, or undergone wear, it tends to become loose and cause noise due to increased movement of the ARB.

Knocking Creaking when turning the steering

  • This case applies to only those vehicles that have a MacPherson Strut front suspension
  • In the MacPherson Strut front, the Top Strut Mount also performs the duty of steering since it is rigidly attached to the wheel Hub. 
  • The Strut Top mount contains a Bushing as well as a bearing that allows the strut to rotate while steering
  • In a majority of cases, when the Top Strut mount is damaged, the bushing and the bearing fail together. This restricts the strut and wheel hub from rotating during steering. 
  • When the bearing fails, it causes knocking and creaking noises while steering especially in low speeds and parking.
  • The Top Mount Bushing failure causes Knocking and Popping noises whilst driving on rough roads.
  • The Strut Top Mount is assembled with the Front Shock Absorber Strut. So for removing this, you would need to disassemble the Front Strut.

Suspension that feels Bouncy and Squeaky

  • In some vehicle the same problem might appear as Knocking and Popping Noises from the Front/Rear while driving over bumps
  • The Bouncy Ride is a sign that points to possible Shock Absorber failure.
  • Part of the noises coming from the suspension are due to the loss of damping action of the shock absorber allowing the wheels to travel more and contacting the bump stops more often. 
  • In most cases, the noises also come partly from the shock moving and hitting against the mounting brackets. The worn out shock mounting bushes would allow this movement.
  • For vehicles that have crossed 40-50K miles, the shock absorbers would have reached their end-of-life. Gradually, owing to long-term internal wear, the shock absorber starts to lose its damping action.
  • In some cases, the shock absorber Top-seal fails and starts leaking oil. In this case also, the shock absorber will lose all damping action.
  • In order to ascertain whether your shock has failed or not you can do a simple “Bounce Test”. 
    • Apply all of your weight on one of the front corners of the vehicle pushing it downwards. 
    • Keep oscillating the corner upwards and downwards till you feel that it has reached its maximum height. 
    • Now you take your hands off the corner and observe how the body settles. 
    • If it takes more than 1 oscillation (once fully up and fully down) to settle, then it means that the damper has failed.

Knocking noises while normal driving

  • Knocking Noises are heard whether driving on a normal road or over a Rough Patch
  • In the cases of extreme wear out, the steering feels hard to control
  • The lower control arm ball-joints (and upper control arm ball-joints in the case of a double-wishbone-type suspension) are subject to wear and tear.
  • Ball-joints are generally protected by means of a rubber boot seal and retains the lubrication within the ball-joints and prevents dust and water from entering the joint.
  • The failure of a ball-joint is usually initiated as a crack or rupture in the rubber boot around the ball-joint
  • This rupture leads to the escape of lubricant from the ball-joint and finally to lead to its complete wear out
  • The wear out causes play between the ball and socket accompanied by knocking noise. The play in the ball-joint is one of the reasons for the vehicle steering feeling vague
  • You can easily check for Ball-joint condition by this simple procedure:
    • Get the car on a lift that will hoist by the body
    • Lock the steering wheel
    • Hold the front tire with both your hands in a 6 o’clock position and try to move the wheel vertical up and down
    • If you hear a ‘Knock’ or ‘Click’, then it is very much likely that the noise is due to a play in the Ball-joint
  • Due to the worn out ball-joint, the Lower control arm is now having play at the bushing and ball-joint locations and therefore the lower arm is not anchored to the subframe properly. The ball-joint play also leads to wheel wobble. Poor handling of the car is due to these factors

Poor handling response

  • In a majority of cases, Poor handling would also be accompanied by an uneven Front Tire wear issue
  • The presence of a Front Tire wear issue, is a clear sign that the alignment of the front suspension is not within the recommended settings.
  • The cause for the change in alignment settings is closely related to the poor condition of the Lower control arm Bushings and Ball-joints
  • When the tires experience lateral contact forces during cornering maneuvers, the play caused by worn out bushes allows the suspension to move out of its alignment settings and, in turn, cause premature and uneven tire wear.
  • Due to the worn out bushings the Lower control arm is now having play at the bushing and ball-joint locations and therefore the lower arm is not anchored to the subframe properly. 
  • The car’s Poor handling response is a result of, mainly, the control arm bushing wear-out.
  • In case of a Rear Uneven Tire wear issue, the most probable cause would be a worn out rear suspension control arm.
  • The rear suspension responds to lateral cornering  loads through the stiffness of the control arm bushings. If the bushes have worn out, it would cause excessive play of the rear wheels in the lateral direction as well as roll.
  • Check all the rear suspension bushings for cracks or disintegration.

Suspension Warning message

  • A Suspension warning message generally appears in vehicles that have an electronically controlled suspension system like a pneumatic or a hydraulic suspension system which comes with built-in diagnostics. These are mostly cars of the luxury category.
  • While the actual words in the warning message would vary from one vehicle to another, the most common messages would look like, “Immediate Service/Repair Required”. Vehicles with an older suspension system would flash a warning message light on the Dashboard.
  • The advantage of an electronically controlled suspension system is that you can pinpoint the actual cause using the manufacturer recommended diagnostic tool plugged in through the OBD II port
  • Most air suspension systems have a similar system layout, and the diagnostics would therefore point you to some standard trouble points like:
    • Air Compressor malfunction
    • Air Strut leakage
    • Valve Block blockage
    • Air-line leakages
    • Ride height sensor malfunction

Conclusion

In this brief article we have discussed the signs that your car’s suspension is bad, and how to troubleshoot these signs.

Please feel free to ask in case of any questions or comments.

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