In this brief article we are going to discuss what are the most common suspension problems in cars, and what symptoms indicate these problems.
What are the Most common suspension problems found in cars?
The most commonly occurring suspension problems are:
- Anti Roll Bar Drop Link Failure
- Anti Roll Bar Bush Failure
- Strut / Shock Absorber Failure
- Rear Shock Absorber Failure
- Spring Breakage
- Strut Top Mount Failure
- Front Lower Control Arm Failure
- Rear Lower Control Arm Failure
Anti Roll Bar Drop Link Failure
- ‘Clunking’ Noise while driving
- Noise is very less on a smooth road and more apparent when driving over a rough patch
Troubleshooting Anti Roll Bar Drop Link Failure
- Rear Knocking sounds that increase on a rough road are the signs that point to an issue with the Anti-roll bar(ARB) links
- The anti roll bar does not articulate so much on smoother surfaces and hence is less noisy
- An easy way to check the ARB linkages is to hold each link and shake it by hand observing for movement or noise at each linkage point.
- The perfect way would be to remove the ARB Drop Links and check the ball-joint for excess play
Anti roll bar bush failure
- The Anti-Roll bar (ARB) bushings are the isolators between the ARB and the vehicle’s chassis. The bushings also ‘secure’ the ARB in place and restrict excessive movement so that the ARB can properly function
- The ARB is under torsional loads while the car is undergoing “Roll” motion either during cornering or Rough Roads.
- In these situations, when the ARB undergoes torsion, the mounting bushes also share part of the road loads.
- Bushings that have aged, hardened, or simply worn out and become loose tend to cause noise as they allow unnecessary movement of the ARB.
- The ARB-to-suspension connection is done using ARB end links.
- On the front axle, the end links use a sealed ball joint design that has a significant range of motion sufficient for the various movements of the front suspension.
- The rubber boot that protects the end link Ball-joints can tear, allowing the joint lubrication to seep out and exposing the ball joint to corrosion. The result is a clunking noise from the worn joint.
- If the end links’ mounting fasteners have loosened on either end, it could result in clunking noise.
- On the rear suspension ARB end links, rubber bushings are used instead of ball joints. These end link bushings can age and then start to squeak.
- Use of Lubricants could temporarily solve the squeaking sound problem. But it is always recommended that new end links be fitted.
Strut / Shock Absorber Failure (Front MacPherson Type)
- Front end feels Bouncier going over bumps
- On a rough road it feels as if the front end is losing grip as you increase speed
- Poor Handling
- Knocking and squeaking noises from the front
Troubleshooting Front Strut Failure
- If your vehicle has crossed 50K miles, then it could be due for a shock replacement. Due to long-term internal wear, the shock starts becoming ineffective over time.
- If the front strut shock has started leaking oil due to a failed oil-seal, then it means that the shock will no longer be effective.
- One good way to tell if your shock has failed or not is to do a Bounce Test. Put all your weight on one of the front corners of the vehicle pushing it downwards. Keep oscillating the corner till you feel that it has reached its maximum height. Once you take your hands off the corner, observe how it settles. If it takes more than 2 oscillations to settle, that means the damper has failed.
- Once the Strut Shock absorber has been dismantled, there is one more way to see the shock condition for yourself by way of a ‘Compression’ test.
- You can simply apply force on the top of the shock and compress it. If it can come back up on its own, then the shock is in fairly good condition. But if it takes too long or doesn’t expand on its own, it’s confirmed that the shock absorber has failed.
Rear Shock Absorber Failure
- Knocking and Popping Noises from the Rear going over bumps
- Rear end feels bouncier
Troubleshooting Rear Shock Failure
- The Bouncy Ride symptom points to the Shock Absorber as a probable cause.
- The noises coming from the rear are partly due to the failed shock absorber allowing the bump stops to contact more often. And also the noises partly come from the worn out shock mounting bushes that allow the shock to move and hit against the mounting brackets.
- If your vehicle has crossed 40-50K miles, then it could be due for a shock replacement. Due to long-term internal wear, the shock starts losing its damping action over time.
- If the rear shock has started leaking oil due to a failed oil-seal, then it means that the shock will no longer be effective.
- One good way to tell if your shock has failed or not is to do a “Bounce Test”, before removing the Shock, or a “Compression test” after removing the Shock
- You would notice a sudden drop in suspension height on any one corner. This can be easily verified by measuring the wheel center height from any reference on the body like the Fender edge.
- Rattling, Squeaking, Creaking noises while driving which are louder when driving over a Bump
Troubleshooting Spring Breakage
- In a majority of cases, the spring fails due to the combined effects of corrosion & fatigue over a period of time.
- The service life of the spring depends on whether the car is used over roads that have salt or in an atmosphere where there is a lot of moisture.
- For replacing the Spring from a strut, you need to first compress the Spring in a spring compressor. You can either use a hydraulic compressor (preferred) or a Threaded Bolt type as well
Strut Top Mount Failure (MacPherson Type)
- Knocking Noise while going over Rough Road Patches
- Bumping/Knocking Noises when trying the lock steering in parking
Troubleshooting Front Strut Top Mount Failure
- The Top Strut Mount contains a Bushing as well as a bearing that allows the strut to rotate while steering
- Generally, when the Top Strut mount is damaged, both the bushing as well as the bearing fail and restricts the strut from rotation during steering.
- The bearing failure causes the knock and creak noises while locking the steering.
- The Bushing failure causes the Knocking and Popping noises driving over a rough patch.
- The Strut Top Mount is assembled with the Front Shock Absorber Strut. So for removing this, you would need to disassemble the Front Strut.
Front Lower Control Arm Failure (MacPherson Type)
- The car seems to be drifting
- Steering seems vague while Lane Changing
- Uneven Tire Wear pattern
- Knocking Noises while going over Rough Patches
- Due to a Tire wear issue, it can be inferred that the alignment of the front suspension is outside of the recommended settings. But this is still a symptom.
- The cause for the change in alignment is closely related to the Lower control arm Bushings and Ball-joints that may have got worn or damaged
- With worn out bushings and ball-joints, when the tires experience lateral contact forces from the road, the play caused by worn out bushes/ball-joints allows the suspension to move out of its alignment and cause premature tire wear.
- Due to the worn out bushings and ball-joints, 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
Troubleshooting Front Lower Control Arm Failure: Lower Control Arm Bushing
- Lower Control Arm bushing wears out over time and cracks due to age
- To assess the bushing condition, you can use a Pry-bar and insert it between the Lower control arm and the Subframe. Now, try to move the Lower Control arm using the Pry-bar and observe the movement at the Bush location. If the lower control arm moves without much force, then it means that the bushes have worn out.
- When inspecting the Lower control arm after removal, it is clear that there are tears and cracks in the rubber portion.
Troubleshooting Front Lower Control Arm Failure: Lower Control Arm Ball-Joint
- The lower control arm ball-joints are also subject to wear and tear.
- The deterioration is usually initiated as a crack or rupture in the rubber boot around the ball-joint
- This leads to loss of lubrication and finally to complete wear out
- The wear out causes play or movement accompanied by knocking noise. The play in the ball-joint is one of the reasons for the vehicle steering feeling value
- You can easily check for Ball-joint condition by this simple procedure:
- Get the car on a Ramp
- Lock the steering wheel
- Hold the front tire with both your hands and try to steer the wheel
- 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
- The best course of action would be to replace the whole Lower control arm since it comes with 2 new bushings and 1 new ball-joint all pre-assembled
Rear Lower Control Arm Bushing Failure (Rear Independent Type)
- Uneven Rear Tire Wear
- Poor Handling; Rear end rolls excessively
- Rear Knocking noises driving over rough surfaces and Bumps
Troubleshooting Rear Lower Control Arm Bushing
- The ‘Camber’ setting of the rear Wheels is influenced by the Lower Control Arm bushings.
- If the Lower Control arm bushings have worn out, the rear wheels go out of alignment, resulting in Uneven Tire wear
- The Lower Control Arm bushings also resist lateral movement of the Tires.
- Failed bushings would allow excessive lateral movement of the tires and adversely affect handling of the vehicle.
- It would be best to replace the Lower Control arms along with the bushings
In this brief article we have discussed what are the most common suspension problems in cars, and what symptoms indicate these problems.
Please feel free to ask in case of any questions or comments.