How to Isolate Suspension Noises

Making the Correct Diagnosis

Finding the source of a suspension noise complaint can seem like a daunting task. To make the job easier, isolating where the noise is coming from will help you make an accurate diagnosis. Start by determining if the noise is coming from the front or back of the vehicle. Having an idea of the general area will help you know how to proceed. For noises originating from the front of the vehicle, it can be helpful to perform a dry park test while pushing on the back of the vehicle can help isolate rear suspension sounds.

What is a Dry Park Test?

Performed on a drive-on rack with an assistant in the vehicle, a dry park test is helpful in finding the source of suspension noise in the front of the vehicle. This test can help you find loose and worn suspension components such as:

• Inner and outer tie rod ends
• Upper and lower ball joints
• Rack and pinion bushings
• Broken, worn or missing components

How to Perform a Dry Park Test

Step 1

Have the vehicle lifted on a drive-on rack with your assistant inside the vehicle.

Step 2

Standing under the vehicle, do a visual inspection looking for:

• Broken sway bar links
• Worn boots on ball joints and tie rod ends
• Worn or oil-damaged boots on inner tie rod ends

Have the assistant in the vehicle move the steering wheel left to right while looking for visual movement of the ball joints.

Step 3

Grab the outer tie rod while the assistant is moving the steering wheel. Feel for looseness and listen for any noises. Visually look at the lower ball joints for looseness. Feel the lower control arm for looseness and listen for any noises.

Step 4

Jack up the wheel under the lower control arm. Grab the tire at 12 and 6 and pushing in at the top and pulling out at the bottom. Under the vehicle, look for ball joint movement. If movement is seen, follow the OE specifications for resolving.

Step 5 

Grab the tire at 3 and 9 and push and pull from side to side. Looking for any looseness on the inner and outer tie rod end.

How to Isolate Rear Suspension Noises

If you suspect that the noise is coming from the rear suspension, a closer look will help isolate the problem. With the vehicle on the rack, have an assistant push up and down on the rear of the vehicle. Standing under the vehicle, do a visual inspection looking for missing, worn or damaged components. 

Getting the Repair Done Right

Once you have pinpointed the source of the noise, you’ll be able to identify what needs to be repaired. Getting the repair done right the first time reduces the chance of customer comebacks and ensures that your customers are satisfied.

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The content in this article is for informational purposes only. You should consult with a certified technician or mechanic if you have questions relating to any of the topics covered herein. Tenneco will not be liable for any loss or damage caused by your reliance on any content.