How do I know if my Subaru axle is bad?
A bad Subaru axle (CV axle) typically shows a torn boot with grease leakage, a clicking noise when turning, and/or vibration or shudder during driving. If you notice these signs, inspect the axle area and consider a professional assessment to prevent further drivetrain damage.
Key symptoms to watch for
These are the most common warning signs reported by Subaru owners. If you notice any of them, schedule a check with a mechanic or Subaru specialist.
- Clicking or popping noises when you turn at low speeds, especially from the front wheels.
- Vibration or shuddering during acceleration or at highway speeds.
- Grease around the wheel hub or a visibly torn or leaking CV boot.
- A clunk or thunk when accelerating from a stop or during gear changes.
- The vehicle pulls to one side or feels loose or unstable while driving, which can indicate a worn joint or imbalance.
Concluding: If you encounter these symptoms, it’s a strong signal that the CV joint or axle may be failing and warrants inspection to avoid further drivetrain damage or a roadside failure.
Visual and hands-on checks you can perform
Before you head to a shop, you can do a careful visual inspection and basic tests to gauge the situation. Always prioritize safety—use a proper lift or jack stands if you plan to inspect under the car.
- Inspect CV boots for cracks, tears, or holes. A torn boot allows dirt ingress and grease loss, which accelerates joint wear.
- Look for grease splatters or buildup around the wheel hub, inner joint area, or along the underside near the CV boot.
- With the vehicle safely supported, gently move the axle near the joint by hand. Excessive play or a noticeable clunking sound can indicate a worn joint.
- Perform a controlled road test: in a safe area, drive straight, then hard-turn left and right at low speed. Listen for clicking, popping, or grinding noises and note any vibration.
- Differentiate from other susbystems: rule out wheel bearings, brakes, or tire issues by noting whether noises persist only during turning (CV issue) versus during braking or at straight-line speed (other components).
Concluding: Visual boot damage and audible or vibrational symptoms during turns are strong indicators that a CV axle or joint is failing. A professional inspection will confirm the extent of the wear and whether an axle replacement is needed.
Diagnosis and repair options
What you can expect in terms of fixes, depending on what’s worn or damaged.
- CV axle replacement (half shaft): The most common fix when the joint has worn beyond boot repair. Replacing the entire axle assembly restores balance and joint integrity.
- CV boot replacement (with re-greasing): If the joint itself is still healthy and the boot is torn early, it’s possible to replace just the boot and re-pack grease, though this approach carries risk if dirt has entered the joint.
- Component compatibility: For Subaru AWD systems, technicians often replace both front axles if wear is present on multiple joints to maintain even handling and avoid imbalance.
- Associated wear: In some cases, the inner joints or axle bearings may be worn, requiring more extensive axle service or replacement.
Concluding: In most cases, replacing the affected CV axle (half shaft) is the simplest, most reliable fix once the joint shows significant wear. Boot-only repairs are reserve options when wear is limited and diagnosed early.
Estimated costs and what affects price
Costs vary by model year, whether you’re replacing front or rear axles, and labor rates in your area. Here are rough guidelines to plan your budget.
- Front CV axle replacement: Parts generally range from budgets around a few dozen dollars for a boot kit to several hundred dollars for a full axle assembly, with labor typically adding a few hundred dollars. Expect total per-axle ranges roughly in the hundreds to near a thousand dollars depending on parts quality and region.
- Rear CV axle replacement: Similar ranges to the front, though some Subarus have different axle configurations that can affect price.
- CV boot replacement (boot kit only): Parts are relatively inexpensive, but labor can be significant because it may require removing the axle and repacking grease. Overall cost is usually lower than a full axle replacement if the joint remains sound.
Concluding: If your CV joint is severely worn, replacing the axle is typically more cost-effective and reliable than boot-only repairs over the long term. Getting a precise quote from a Subaru-certified shop will help you compare options.
Safety and practical guidance
Driveability issues tied to a bad axle can lead to loss of control or further damage. If you hear grinding, notice sudden vibrations, or see a torn boot with grease leakage, minimize driving and arrange a professional inspection as soon as possible.
When to seek professional help
If you’re unsure about the diagnosis, or the symptoms persist after a boot repair or basic inspection, consult a qualified technician or Subaru dealership. They can perform a comprehensive inspection, confirm joint wear, and advise on whether an axle replacement, boot replacement, or more extensive drivetrain service is needed.
Summary
A bad Subaru axle commonly presents with a torn CV boot, grease leakage, clicking noises when turning, and vibration during driving. Start with a visual boot check, listen for turning noises, and test drive carefully to observe symptoms. If a boot is torn or the joint shows play or abnormal vibration, plan for axle replacement or boot repair performed by a qualified mechanic. Costs vary widely, but replacing the axle is often the most reliable long-term solution, especially on all-wheel-drive Subarus. Regular maintenance and prompt attention to boot damage can prevent more serious drivetrain trouble and keep your Subaru performing safely.
How long do Subaru axles last?
80,000 to 100,000 miles
The lifespan of your CV axle is typically fairly long, withstanding 80,000 to 100,000 miles under regular driving conditions. If you begin hearing a loud, rhythmic clicking noise as you turn, it's a good sign the axle is failing.
How to tell if a Subaru CV axle is bad?
But I don't get much noise but then if I turn. It. You hear that rumble and feel that rumble that's the U-jints. Trying not to break in half. So if when you're driving straight. Ahead.
What are the symptoms of a bad axle?
Symptoms of a bad axle include clicking or popping noises when turning, vibrations or shaking during acceleration, grease leaking from the CV joint boots, and a clunking sound when shifting into gear. Other signs are difficulty steering, uneven tire wear, and a wobbling wheel.
Audible symptoms
- Clicking or popping: A repetitive clicking or popping sound, especially during sharp turns, is a classic sign of a worn outer CV joint.
- Clunking: A loud clunking noise can occur when shifting into gear, or it may be heard after hitting a bump.
- Grinding or crunching: A grinding or crunching noise can indicate that the internal joints are failing.
Visual and tactile symptoms
- Grease leakage: A common indicator is grease splattered around the inside of a wheel or visible puddles of grease under the car. This happens when the rubber CV joint boot tears, allowing the grease to escape and dirt to enter.
- Vibration or shaking: You may feel a vibration, especially when accelerating or at higher speeds, that can be felt in the steering wheel or throughout the vehicle.
- Uneven tire wear: A failing axle can cause misalignment, which leads to uneven and premature tire wear on one or more tires.
- Wobbling wheel: You might notice the wheel itself appears to be wobbling, especially at speed.
Performance and handling symptoms
- Difficulty steering: A damaged axle can make steering feel stiff or sluggish.
- Sluggish performance: The car may feel slow to accelerate or less responsive.
- Vehicle won't move: In the worst-case scenario, a completely broken axle will prevent the vehicle from moving at all.
How to tell if a Subaru wheel bearing is bad?
Common Subaru wheel bearing symptoms include loud humming, grinding, or clicking noises that change with speed or turning, vibrations felt in the steering wheel or cabin, loose steering or pulling to one side, and uneven tire wear. The ABS light may also illuminate if the bearing's excess play damages the wheel speed sensor.
Auditory symptoms
- Humming or grinding: A common sign is a loud, rhythmic humming or grinding noise that intensifies with speed.
- Clicking or popping: You may hear a clicking or popping sound, especially when turning.
- Noise changes with turns: The noise often gets louder when turning in one direction and quieter when turning the other, as weight shifts to one wheel.
Driving and handling symptoms
- Vibrations: A vibrating or shaking sensation in the steering wheel or the car's body, particularly at higher speeds.
- Pulling: The vehicle may pull to one side, especially when braking.
- Loose steering: The steering may feel loose, with unusual play when you turn the wheel.
- Wobbling: The wheel might wobble or feel loose.
Other symptoms
- Uneven tire wear: Look for abnormal or uneven wear patterns on your tires, as this is a key indicator.
- ABS light: The Anti-lock Braking System (ABS) warning light can come on if the bearing's failure causes the wheel speed sensor to malfunction.
- Decreased handling: Overall handling performance may feel decreased, making the car feel less stable during turns.
