Usually, yes — if one MacPherson strut on an axle fails, replacing both on that axle is the common recommendation to maintain balanced damping and stable handling. There are exceptions, but the risk of ongoing imbalance makes the paired replacement the safer, more predictable choice.
This article explains how to evaluate your situation, what to look for in signs of failure, when to replace both versus one, and what to expect for cost and service.
Key indicators that a strut may be failing
Before you decide on replacing one or both, look for these indicators that a strut is failing or near the end of its service life:
- Leaking hydraulic fluid around the strut seal
- Excessive bouncing or poor ride quality after hitting bumps
- Knocking, clunking, or squeaking noises when driving over uneven pavement
- Uneven or rapid tire wear on the same axle
- Visible damage, corrosion, or a bent or misaligned strut body
If you notice these signs, have a qualified mechanic inspect both struts and related components such as mounts, bushings, and springs.
Reasons to replace both struts on the same axle
Replacing both struts on the same axle is generally advised to keep the suspension balanced and predictable. Here are the key reasons:
- Ensures balanced damping and ride height between the two sides
- Prevents uneven tire wear and potential steering drift caused by a damping imbalance
- Reduces the risk of future alignment issues after suspension work
- Can prevent additional labor and part costs from replacing one side later
- Maintains similar wear characteristics if both struts are of similar age and usage
Keep in mind that some vehicles with independent damping or certain suspension designs may tolerate replacing only one strut, but the overall consensus among many shops is to replace in pairs for axle-based setups.
Design and vehicle-type considerations
In some suspensions, such as certain independent setups or performance-oriented designs, a single-strut replacement might be feasible without immediate safety concerns. For most passenger cars with a shared axle, however, replacing both remains the safer and more reliable option.
When you might opt to replace just one
There are scenarios where replacing only the failing strut may be reasonable, such as when the other strut is very new or if a quick, low-cost repair is needed and you plan a future replacement. Consider these factors:
- The other strut shows no signs of wear or damage and is near the end of its service life only by age
- You are budgeting temporarily and plan to replace the second strut later
- You are using aftermarket parts with different warranties or performance characteristics
Discuss with your technician whether a phased approach makes sense for your vehicle, driving needs, and budget. If you only replace one, plan for a possible immediate alignment check and road test to verify stability.
Cost, parts options, and service considerations
Costs vary by brand, vehicle, and location. Here is a rough guide to what you can expect and factors that affect price:
- Parts options: strut assemblies (complete with mount and spring) vs. dampers only; OEM vs aftermarket; some vehicles require special components
- Typical pricing: per strut assembly in the United States can range from about $100 to $600 for parts, plus $150–$350 per strut for labor; replacing both on one axle often totals roughly $600–$1,800 depending on the vehicle and parts
- Alignment and related items: a wheel alignment is usually recommended after replacing suspension components and may cost $75–$150
- Additional parts: worn mounts, bushings, or coil springs may be replaced during the service, adding to cost
For accuracy, request a written estimate that includes parts, labor, and potential alignment. Discuss warranties on the parts and labor, especially for aftermarket components.
What to expect during a replacement
When you replace struts, mechanics typically perform a multi-step process to ensure proper function and safety:
- Inspect the suspension components for wear beyond the struts themselves
- Remove the old struts and mounts and install new strut assemblies or dampers
- Check and adjust ride height if necessary
- Perform a wheel alignment after completion
- Test-drive the vehicle to verify handling and absence of unusual noises
Ask your shop to explain whether they replaced mounts or springs as part of the service, and confirm whether an alignment was performed.
Summary
In most cases, replacing both struts on the same axle when one is bad yields better handling, more even tire wear, and fewer future service visits. If the other strut shows no signs of wear and is relatively new, a single-strut replacement might be reasonable, but the safer, more common route is to replace both. Always have a professional assess the entire suspension and consider road use, vehicle age, and desired ride quality when deciding.