In this brief article we are going to discuss the probable causes for suspension creaking and tips on how to troubleshoot these causes.
What are the most common causes for Creaking in your car’s suspension?
There are a variety of reasons why a car‘s suspension creaks. The most commonly reasons for suspension creaking are:
- Failed Strut Top mount bearing
- Broken Coil Spring
- Leafspring interleaf rubbing
- Failed Shock Absorber
- Conical Rubber Bushing Friction
Failed Strut Top Mount Bearing
- 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.
- The Strut Top Mount is assembled with the Front Shock Absorber Strut. So for removing this, you would need to disassemble the Front Strut.
Troubleshooting a Failed Strut Top Mount Bearing
- The most sure sign of a failed top mount bearing is to check for creaking noises when trying to steer the vehicle while parking
- During low speed driving, creaking while steering is a sign of sturt top mount bearing failure
Broken Coil Spring
- The Suspension creak is more noticeable every time the wheel goes over even small bumps
- The sound is almost like a ’Haunted House’ door hinge
- The Creaking noise is cause by the spring’s broken edges rubbing while the suspension goes up and down.
Troubleshooting a Broken Spring
- Springs do tend to break after a certain mileage
- One easy way to identify a broken spring is to park the car over a flat surface and measure the fender height from the ground for all the corners.
- Compare the measured values of the left side and right side suspension. If there is a difference of 1 inch or more, it could most probably imply a broken spring.
- Inspect the springs on both sides close to the bottom and Upper mounts as well.
Leafspring Interleaf Rubbing
- This is maily for Pickup trucks and SUVs that have a rear Leafspring suspension
- The most common symptom is that the Rear end creaks during normal driving
- The creaking increases when the truck is unloaded as compared to when it is loaded
Troubleshooting Leafspring Interleaf Rubbing
- The crueaking in a LeafSpring is due to one of two reasons:
- Interleaf friction
- Failed front Hinge Bushing
- The leaf spring pack works together to provide the required suspension stiffness
- In this process, the leafs contact and cause friction and noise
- The manufacturer provides rubber spacers to reduce noise, but these wear out over time
- One solution would be to replace the rubber spacer pads
- The other would be to regularly apply grease to the interleaf contact surfaces
- Check also the condition of the leaf front hinge/hanger Rubber bushing. This consists of a steel bearing tube with 2 conical rubber bushings fitted around the tube
- If the bushing does not come out easily, you may need to use a Press-kit with an appropriate size collar
- If the press-kit is not working, then you could you could use a torch and heat up the eye of the leaf spring just enough to melt the rubber and push it out
Failed Shock Absorber
- 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.
- Another possibility is, if the front strut shock has started leaking oil due to a failed oil-seal, then it means that the shock will no longer work in the absence of oil.
- In both of the above cases, the shock absorber internal piston would start to rub against the inner tube, the rod would rub against the Road-seal and cause creaking noises.
Troubleshooting Failed Shock Absorber
- 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. First check for the source of the creaking noises, if it happens to be close to the shocks.
- 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.
Conical Rubber Bushing Friction
- If the creaking is due to bushings, the creaking noise happens during normal driving
- The Creaking is heard even on a smooth road
- This mostly implies that the creaking is coming from one or more of the suspension bushings
- This is especially the case for those suspensions that have ‘Conical’ Donut shaped Rubber bushings that are axially compressed under normal tightening of the bushing joint.
Troubleshooting Conical Rubber Bushing Friction
- In order to identify where exactly the Creaking is coming from, you can simulate the suspension movement under weight and closely observe the squeak closely
- For this, lift your rear body and place it on Jack-stands
- Now use a hydraulic jack to lift and lower the rear wheel hub to simulate suspension movement
- Move the rear wheel carrier up and down a few times and listen closely for the source of the squeak noise.
- If needed, you can use a long shaft Screwdriver and place the handle at your ear while the tip is at various suspension mounting points.
- Lower Control arms are known to squeak from past experience
- If the bushing is still intact and in working condition, you can try a “Quick-Fix” solution to eliminate the noise problem
- Use a Pointed tool to poke holes into the exposed Rubber Portion of the Bush
- Spray a long-lasting lubricant like WD 40 or Wurth ultra 2040 into the new bushing holes using a nozzle
- Once again, using the Hydraulic Jack, move the rear wheel carrier up and down in order to let the lubricant spread throughout the joint.
- Lower the vehicle and see if the problem has been eliminated in normal driving
In this brief article we have discussed the probable causes for suspension creaking and tips on how to troubleshoot these causes.
Please feel free to ask in case of any questions or comments.