Subaru Forester CV Axle Replacement: The DIY Guide You Need

Ever noticed a clicking noise when turning your Subaru Forester? Or maybe you’ve spotted mysterious grease on your wheel rims? These are telltale signs of CV axle problems. I’ll walk you through everything you need to know about CV axle replacement on your Subaru Forester—from diagnosing the issue to getting the job done right. Let’s dive into this critical maintenance task that’ll keep your Subie running smoothly for miles to come.

What Are CV Axles and Why Do They Matter?

CV (constant velocity) axles are the unsung heroes of your Subaru’s drivetrain. These components transfer power from the transmission to your wheels while allowing for suspension movement and steering. Think of them as the flexible connectors that make your all-wheel-drive system possible.

In your Forester, these axles typically last between 80,000 to 100,000 miles under normal conditions. But if you’re hitting rough roads frequently or have an aggressive driving style, you might see issues earlier. The CV joints at each end of the axle contain ball bearings held together by grease-filled rubber boots—and when these components fail, problems start.

5 Warning Signs of Failing CV Axles

Your Subaru will usually give you several hints when a CV axle is on its way out. Here’s what to watch for:

1. Clicking Noises During Turns

The most obvious symptom is a repetitive clicking or clunking noise when turning, especially during acceleration. This sound gets louder as you make sharper turns and becomes more rapid as your speed increases. This noise specifically points to wear in the outer CV joint, where the constant flexing during turns has caused excessive play in the ball bearings.

2. Grease Leakage

Take a look behind your wheels. See dark grease splattered on the inside of your rim or on nearby suspension components? That’s a dead giveaway of a torn CV boot. These protective rubber covers hold special grease that keeps the joints lubricated. When they tear, grease escapes and dirt gets in—a recipe for rapid joint failure.

3. Vibrations During Acceleration

Feel your steering wheel or the entire vehicle shake when you press the gas? While this could be caused by several issues, CV axle problems are a common culprit. The vibration typically intensifies with speed and indicates looseness in the CV joint connections.

4. Clunking When Shifting

A failing inner CV joint might cause a clunking noise when shifting from drive to reverse or when initially accelerating from a stop. This happens because worn components allow too much movement within the joint.

5. Difficult Steering

In advanced cases, deteriorated CV joints can cause steering resistance or pulling to one side. This happens when the joint no longer moves smoothly through its range of motion.

DIY Diagnosis: Is It Really Your CV Axle?

Before you start ordering parts, let’s confirm the problem. Here are some simple tests you can perform:

The Parking Lot Test

Find an empty parking lot and drive your Forester in slow, tight circles while gently accelerating. Turn both left and right. A bad CV joint will produce distinct clicking noises that match your turning radius—the tighter the turn, the more pronounced the clicking.

Visual Inspection

Jack up your Forester (safely, with proper jack stands) and examine the rubber boots on each end of your CV axles. Look for:

• Tears or cracks in the rubber
• Grease leakage
• Damaged clamps that secure the boots

Grab the axle and try to move it side-to-side. Excessive play might indicate a worn joint.

Rotation Test

With the car safely supported and the wheel off the ground, rotate the wheel by hand. Listen for grinding or feel for roughness that might indicate damaged bearings within the CV joint.

Replacement Cost: OEM vs. Aftermarket Options

The cost of CV axle replacement varies widely depending on your choice of parts and whether you DIY or visit a shop. Here’s a breakdown:

While aftermarket parts might seem tempting at first glance, there’s a reason for the price difference. Many Subaru owners report premature boot failure or joint problems with aftermarket axles within 5,000-10,000 miles. If you plan to keep your Forester long-term, OEM parts often provide better value despite the higher initial cost.

Tools You’ll Need for DIY Replacement

If you’re tackling this job yourself, gather these tools before starting:

• 32mm axle socket (or deep socket)
• Breaker bar or impact wrench
• Torque wrench
• Jack and jack stands rated for your vehicle’s weight
• Wheel chocks
• Socket set and wrenches
• Pry bar
• Hammer
• Penetrating oil
• Safety glasses and gloves

The 32mm socket is particularly important—this specialty tool is required for the axle nut and might be worth borrowing or renting if you don’t own one.

Step-by-Step CV Axle Replacement

Ready to get your hands dirty? Here’s how to replace a CV axle on your Subaru Forester:

1. Preparation

• Park on a level surface and engage the parking brake
• Loosen (but don’t remove) the wheel lug nuts
• Safely jack up the vehicle and secure it on jack stands
• Remove the wheel

2. Access the Axle

• Remove the cotter pin from the axle nut (if present)
• Use your 32mm socket and breaker bar to loosen the axle nut
• Remove the brake caliper (don’t let it hang by the brake line—secure it with wire)
• Remove the brake rotor

3. Disconnect the Steering Knuckle

• Remove the tie rod end from the steering knuckle (mark the position first to maintain alignment)
• Loosen and remove the lower strut bolts (again, mark positions)
• Pivot the steering knuckle downward to create space for axle removal

4. Remove the Old Axle

• Use a pry bar between the axle and knuckle to separate them
• Pull the outer end of the axle free from the hub
• For the inner end, use a pry bar between the axle and transmission housing
• Pull the axle straight out from the transmission (it may require firm force)

5. Install the New Axle

• Align the splines of the inner joint with the transmission
• Push firmly until you hear a distinct “click” indicating proper seating
• There should be no gap between the axle and transmission housing
• Insert the outer end into the hub assembly
• Reinstall the axle nut hand-tight

6. Reassembly

• Reconnect the steering knuckle to the strut (use your alignment marks)
• Reinstall the tie rod end
• Replace the brake rotor and caliper
• Tighten the axle nut to 162 ft-lbs (220 Nm)
• Reinstall the wheel and lower the vehicle
• Torque lug nuts to 89 ft-lbs (121 Nm) in a star pattern

Critical Torque Specifications

Proper torque is essential for safety and component longevity. Here are the key specs for your Subaru Forester:

• Axle nut: 162 ft-lbs (220 Nm)
• Strut-to-knuckle bolts: 115 ft-lbs (156 Nm)
• Tie rod castle nuts: 19 ft-lbs (26 Nm)
• Brake caliper bolts: 59 ft-lbs (80 Nm)
• Wheel lug nuts: 89 ft-lbs (121 Nm)

Always use a quality torque wrench for these critical fasteners.

Model Year Variations to Consider

Subaru Foresters have some important differences across generations:

2014-2018 Generation

These models use standardized CV axles across trim levels, with a professional installation time of about 54 minutes per side. However, turbocharged Forester XT models require different axle part numbers compared to naturally aspirated engines, despite looking very similar.

2011 Models

The 2011 Forester XT uses part number 28321SC003, while non-turbo models use 28321SC033—with approximately $200 price difference between these components.

2019-2025 Generation

These newer models use part numbers like 28321SJ010 for current production, though older part number 28321SJ000 remains available at reduced cost.

Transmission Differences

Foresters with CVT transmissions typically operate with 60/40 front-to-rear torque distribution, potentially causing increased front axle wear compared to manual transmission variants with 50/50 distribution. This might explain why some 2018 CVT-equipped Foresters experience CV joint failure at around 56,000 miles, while manual transmission models often exceed 140,000 miles without problems.

DIY vs. Professional Installation: What’s Right for You?

Before deciding to tackle this job yourself, consider:

Time Investment

While professional mechanics can complete the job in under an hour per side, first-time DIYers should plan for 4-6 hours total. The learning curve can be steep, and unexpected challenges often arise.

Tool Costs

If you don’t already own specialty tools like the 32mm axle socket and a quality torque wrench, the cost of purchasing these items might approach the labor cost of professional installation.

Risk Factors

Improper installation can damage transmission seals, hub bearings, or differential components—potentially leading to expensive repairs. Professional installation typically includes warranties covering both parts and labor.

Space Requirements

You’ll need a clean, level workspace with enough room to safely jack up your vehicle and work around it.

If you’re comfortable with moderate to advanced mechanical work and have the right tools, this is a manageable DIY project. Otherwise, the peace of mind from professional installation might be worth the additional cost.

Preventive Maintenance to Extend CV Axle Life

Want to get the most life from your CV axles? Follow these maintenance tips:

Regular Inspections

Include CV boot checks in your regular maintenance routine. Subaru recommends inspecting CV boots and axles every 15,000 miles as part of your comprehensive drivetrain assessment.

Early Boot Replacement

If you catch a torn boot before the joint becomes contaminated, you can often replace just the boot for $150-$250 instead of the entire axle assembly ($400-$700). This makes regular inspections financially beneficial.

Driving Habits

Reduce stress on your CV joints by:

• Avoiding aggressive acceleration during tight turns
• Minimizing full-lock steering maneuvers when parking
• Being cautious on rough terrain that pushes your suspension to its limits

Environmental Considerations

Vehicles operated in harsh conditions need more frequent inspections. This includes:

• Frequent off-road use
• Mountainous terrain driving
• Areas with heavy road salt use

Making the Right Choice for Your Subaru

CV axle replacement on your Subaru Forester is a significant but manageable maintenance task. By recognizing the warning signs early and making informed decisions about parts and installation, you can minimize costs while ensuring your Subaru’s legendary all-wheel-drive system continues to perform as designed.

Whether you choose the DIY route or professional service, prioritizing quality parts will pay dividends in reliability and longevity. Your Forester was built to last—and with proper CV axle maintenance, you’ll enjoy many more years of that signature Subaru performance and capability.