All Front Wheel Bearing / Hub Assembly Replacement jobs
Front Wheel Bearing / Hub Assembly Replacement
2010–2014 Subaru Outback - 2.5L H4 / FB25
Front hub bearing on a 2013 Outback is a bolt-in cartridge job, not a press-fit like older cars. That's the good news. The bad news: if you live anywhere salty, galvanic corrosion probably welded the old hub into the knuckle bore, and you'll need a slide hammer or hub puller to break it loose. Plan 1–2.5 hours of solid work, mostly waiting for penetrating oil and swearing at rust.
How Rough Is This Going to Be? Know what you're getting into.
This is intermediate work. You're removing the wheel, brake caliper and rotor, unspooling the CV axle, and pulling four bolts to extract the hub bearing cartridge from the steering knuckle. Then you clean, install new, and torque everything back. The procedure itself is straightforward. Rust is the variable. If the hub is seized, you'll need specialized extraction tools. Do not attempt to hammer the old hub out without a proper puller—you'll trash the knuckle ears or break the ABS sensor that lives on the back of the hub.
Save Another Trip to the Parts Store Clips, seals, fluids, and the little stuff people forget.
Unstake the old axle nut before you start jacking. Break the 32mm nut loose on the ground with the wheel still on, then jack. Disconnect the ABS wheel speed sensor (10mm bolt) before you touch the hub—leave it installed and hammer blows will snap the plastic sensor tip off inside the knuckle. Grab a brake caliper hanger to support the caliper so it's not dangling on the brake line. Have fresh penetrating oil on hand for the rotor if it's seized. And buy a new axle nut (OEM 902170049)—reusing the old one will fail.
Here's Where It Gets Greasy The procedure, pain points, and common ways this job fights back.
Using the old staked axle nut a second time guarantees it'll back off and you'll lose a wheel. Mushrooming the axle spindle threads by hammering on the bare shaft end instead of threading the old nut flush first. Not cleaning the knuckle bore before installing the new hub, which leaves the hub cocked and causes brake pulsation and premature failure. Leaving the ABS sensor installed while you're beating on the old hub—plastic sensor bodies don't survive that. And never torque the axle nut then drive the car without staking the collar into the notch, or it'll loosen under load.
Procedure
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1
Front Axle Nut
Loosen axle nut staking collar and crack axle nut loose while vehicle is on ground
Unstake the axle nut flange from the axle shaft keyway with a punch before applying breaker bar torque to avoid galling spindle threads.
Have an assistant step on the brake pedal or break the nut loose with wheel on the ground before jacking up the car.
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2
Front Wheel & Tire Assembly
Lift vehicle safely and remove front wheel
Ensure jack stands are securely placed under designated subframe/pinch weld lift points.
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3
Front ABS Wheel Speed Sensor
Disconnect and remove front ABS wheel speed sensor from steering knuckle
Do not leave the sensor installed in the knuckle during hub removal; shock waves and hammer blows will fracture the plastic sensor body or tip.
Gently wiggle sensor free; if stuck with corrosion, spray penetrating oil around body before pulling.
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4
Brake Caliper and Bracket
Remove front brake caliper and caliper mounting bracket assembly
Never allow brake caliper to hang unsupported by the rubber brake flex hose.
Remove the two 17mm caliper bracket-to-knuckle bolts to remove caliper and carrier bracket as a single unit.
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5
Front Brake Disc / Rotor
Remove brake disc rotor
If rotor is seized to hub face, screw two M8x1.25 bolts into the threaded extraction holes on the rotor hat to push it evenly off the hub.
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6
CV Axle Shaft Spindle
Completely remove 32mm axle nut and push CV axle shaft inward out of hub splines
Do not mushroom axle threads. If splines are tight, thread the old axle nut on flush with end of shaft and tap with a brass drift or soft-blow mallet.
Ensure axle moves freely in and out of the hub splines by at least 1/2 inch before proceeding to hub removal.
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7
Hub Unit Mounting Bolts
Remove four hub unit bearing mounting bolts from rear of steering knuckle
Ensure socket is fully seated on the bolt heads to avoid rounding off 14mm fastener heads.
Turn the steering wheel fully to the side being worked on to gain easier socket and extension access behind knuckle.
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8
Front Hub Unit Bearing and Dust Shield
Extract old hub unit bearing and brake dust cover shield from knuckle bore
Do not strike the aluminum/cast iron knuckle ears directly or pry against ABS mounting flange.
If heavily seized from rust, use a hub puller, slide hammer, or backing plate press bolts to break hub free from knuckle housing.
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9
Steering Knuckle Bore
Clean knuckle bore, splash shield, and spline interfaces
Thoroughly remove all rust scale and debris from knuckle bore surface so new hub seats square and true without runout.
Apply a thin coat of anti-seize or light grease around the outer knuckle bore landing, avoiding the ABS sensor hole area.
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10
New Front Hub Unit Bearing
Install new front hub unit bearing and brake dust cover shield onto steering knuckle
Do not bring magnetic tools near the inboard magnetic encoder seal on the back of the hub assembly. Ensure brake dust shield cutout is clocked correctly before inserting hub.
Guide CV axle splines cleanly into the hub center bore while sliding hub assembly into knuckle.
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11
Hub Unit Mounting Bolts
Torque four hub-to-knuckle mounting bolts to 47.9 ft-lb (65 N·m)
Tighten progressively in a cross pattern to seat hub squarely.
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12
Front ABS Wheel Speed Sensor
Reinstall ABS wheel speed sensor and torque bolt to 5.5 ft-lb (7.5 N·m / 66 in-lb)
Do not overtighten small 10mm M6 fastener in aluminum/cast knuckle.
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13
Brake Rotor and Caliper Bracket
Reinstall brake disc rotor and brake caliper mounting bracket assembly
Torque the two 17mm caliper bracket mounting bolts to 88.5 ft-lb (120 N·m).
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14
New Front Axle Nut
Install new axle nut, torque to 162 ft-lb (220 N·m), and stake collar securely into shaft notch
Always use a new replacement axle nut. Failure to stake the nut properly can lead to backing off and catastrophic hub/wheel detachment.
Use a punch to deform the collar of the nut into the axle spindle slot so rotation is prevented.
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15
Wheel and Lug Nuts
Reinstall wheel and torque lug nuts to 89 ft-lb (120 N·m)
Torque lug nuts in a star/crisscross sequence with vehicle lowered to ground.
Pump brake pedal several times before driving to seat brake pads against rotor.
Gotchas
- Hub frozen in knuckle bore: Galvanic corrosion between the steel hub housing and cast knuckle bore frequently bonds the assembly solid. In salted road regions, a slide hammer, hub press tool, or aggressive bolt extraction method is almost always required.
- Magnetic ABS encoder ring sensitivity: The ABS encoder is built into the back seal of the hub bearing assembly. Touching magnetized tools (like magnetic pickup tools or magnetized sockets) or allowing metal shavings/dirt to adhere to this seal will corrupt wheel speed signals and trigger ABS/VDC error codes (e.g. C0021-C0024).
- ABS sensor breakage: Leaving the wheel speed sensor installed while attempting to hammer out the old hub will shatter or shear the plastic sensor tip inside the knuckle.
- Brake dust shield orientation: The stamped brake backing plate is clamped between the hub flange and the knuckle. It is easy to accidentally orient it backwards or 90 degrees out of phase, requiring full disassembly if realized after tightening hub bolts.
Common mistakes
- Reusing the old staked axle nut instead of installing a new OEM nut (902170049), which weakens the staking flange and risks backing off under load.
- Failing to clean heavy corrosion and scale from the knuckle bore before installing the new hub, causing the new hub to sit cocked, resulting in brake pulsation and premature bearing failure.
- Hammering directly on unprotected axle spindle threads to break the CV axle loose, mushrooming the end threads and preventing nut installation.
- Letting vehicle weight rest on wheels without the axle nut fully torqued down, which can separate the inner bearing races and immediately ruin the new bearing.
It's a Good Idea To... Greasy tips and useful while-you're-in-there advice.
If the hub won't budge after you've removed the four mounting bolts, don't get creative with a hammer and chisel on the knuckle. Spray the bore with penetrating oil, wait 30 minutes, then use a slide hammer or threaded hub extraction kit. If you don't have one, most tool rental shops have them. In a pinch, you can thread two M8x1.25 bolts into the hub face holes and use them to press the rotor hat as a lever—that sometimes breaks the initial corrosion bond. Magnetic tools and metal shavings near the back of the hub will corrupt the ABS encoder ring and throw error codes, so keep your workspace clean and use non-magnetic sockets if you have them.
You Already Have a Screw Loose. Your Car Shouldn't. Final checks before you call it done.
Torque specs: hub bolts to 47.9 ft-lb, axle nut to 162 ft-lb (then stake it), caliper bracket to 88.5 ft-lb, wheel lugs to 89 ft-lb. Clean everything, use a new nut, take your time on the extraction if it's stuck, and pump the brakes before driving. This job is doable solo if you have jack stands and a plan for a seized hub. If corrosion is bad, rent the puller beforehand or save yourself the headache.