2016-2018 Acura RDX Front Struts: Diagnosing the Common Low-Speed Clunking Noise

Known Issues: Front Suspension Noise on the 2016-2018 RDX

A widely reported issue for the 2016-2018 Acura RDX is a distinct noise coming from the front suspension. Owners often describe this as a clunk, rattle, thump, or creak, which is most noticeable when driving at lower speeds over uneven pavement, bumps, or driveway curbs. This problem became common enough that in September 2021, American Honda Motor Co. (AHM) sent a message to dealers to investigate client complaints of front suspension noise on 2017-2018 RDX models before attempting repairs, in order to better understand the root cause. While the struts themselves can be the source, forum discussions and mechanic diagnoses often point to worn strut mounts as a primary or contributing factor to the noise.

Symptoms of a Failing Suspension Strut

When a strut begins to fail, it can produce a variety of symptoms. Some are general to any vehicle, while others are specific to the RDX.

• Clunking or Rattling Noises: The most common complaint for the RDX is a clunking, knocking, or rattling sound from the front end over bumps. This often indicates wear in the strut itself or, very commonly, the upper strut mount.
• Bouncy or Unstable Ride: If your RDX feels overly bouncy and continues to oscillate after hitting a bump, the internal damper has likely worn out and is no longer controlling the spring's movement.
• Nose-Diving and Squatting: Worn front struts will cause the front of the vehicle to dip excessively when you apply the brakes. Similarly, worn rear shocks can cause the back of the vehicle to squat during acceleration.
• Uneven Tire Wear: A bouncing tire, caused by a bad strut, can lead to a specific type of uneven wear called "cupping" or "scalloping," where patches of rubber are gouged out from the tread.
• Visible Fluid Leaks: The strut body contains hydraulic oil. If you see an oily, grimy film on the outside of the strut, it means the internal seals have failed and the strut needs to be replaced.

Buying a Used Suspension Strut for Your RDX

A recycled OEM strut can be a cost-effective and reliable alternative to expensive new parts, especially when dealing with issues like the RDX's suspension noise where using the original factory-tuned part is beneficial. Here’s what to look for:

• Physical Inspection: This is the most important step. Look for any signs of fluid leakage on the strut body. A light film of dirt is normal, but a thick, oily grime indicates a blown seal. Inspect the strut shaft (the shiny piston rod); it should be smooth and free of rust, pitting, or damage that could tear the seals.
• Check for Bends and Damage: Examine the strut housing, spring perch, and mounting points for any signs of bending or cracking, which could indicate it came from a vehicle in a collision. Do not use a bent or damaged strut.
• Mileage and Condition: While there isn't a specific mileage where failure is guaranteed, struts are wear items. Aim for a part from a lower-mileage vehicle if possible. Many RDX owners have reported noises appearing at relatively low mileage, such as 46,000 miles or less. A used OEM strut from a 50,000-mile vehicle is often a better choice than a brand-new, cheaply made aftermarket strut that may not have the same damping characteristics as the original.
• Test the Damping: If the strut is off the vehicle, try to compress and extend the shaft by hand. It should move smoothly with consistent, firm resistance in both directions. If it moves too easily, makes noises, or has dead spots, it is worn out.
• Verify Part Numbers: Ensure the part numbers match your vehicle. For the 2016-2018 RDX, the latest OEM numbers are 51621-TX4-A12 (Left) and 51611-TX4-A12 (Right).

Related Parts to Replace with the Strut

To do the job correctly and avoid future problems, several related components should be replaced at the same time as the struts.

• Replace in Pairs: Always replace both the left and right struts at the same time to ensure even handling and prevent instability.
• Strut Mounts: Given the known clunking issues with the RDX, it is highly recommended to replace the upper strut mounts (Part No. 51920-TX4-A01) when you replace the struts. A worn mount can cause noise, steering binding, and alignment problems.
• Dust Boot and Bump Stop: These protect the strut shaft from dirt and prevent the suspension from bottoming out. They often degrade over time and should be included with a new strut assembly or replaced on a bare strut.
• Sway Bar Links: Inspect the sway bar end links for looseness or damaged bushings. They are inexpensive and easy to replace while the suspension is apart, and can also be a source of clunking noises.

Cost of Replacement (2016-2018 Acura RDX)

Prices can vary based on location and the parts chosen. The following table provides an estimated cost breakdown for replacing a pair of front struts.

Note: Labor costs can vary significantly between independent shops and dealerships. Total replacement cost at a repair shop often ranges from $1,300 to $1,500.

Replacement Overview and Torque Specs

Replacing the front struts on an RDX is a job for an experienced DIY mechanic or a professional. It requires lifting the vehicle, removing the wheel, and disconnecting several suspension and brake components. If you are replacing a bare strut, you will need a spring compressor, which is a dangerous tool if not used correctly. Using a complete "quick-strut" assembly is safer and faster.

Key torque specifications are critical for a safe repair. The values below are based on an official Acura service bulletin.

Frequently Asked Questions