Parts for your 2018 Mazda 3-Wheel bearings

2018 Mazda 3 wheel bearings: purpose, service and replacement

Wheel bearings are absolutely fitted to the 2018 Mazda 3 (BM/BN). Technical sources confirm this: the Mazda Workshop Manual for Mazda3 (2014–2018) details front and rear hub-and-bearing units in the Front Axle and Rear Axle sections, the Mazda Electronic Parts Catalogue lists complete hub/bearing assemblies for both axles, and major bearing catalogues (e.g., SKF, Timken, MOOG) publish specific hub/bearing part listings for this model. So, wheel bearings are relevant and serviceable items on a 2018 Mazda 3.

On this Mazda 3, each wheel spins on a sealed bearing that sits inside a hub assembly. Its job is to carry the car’s weight, keep the wheel tracking true, and let it rotate smoothly with minimal friction. That smoothness protects tyres from scrubbing, keeps fuel use sensible, and helps the ABS and stability control get clean signals from the integrated encoder ring.

The bearings are a unitised, sealed design—there’s no periodic greasing. When they wear, they’re replaced as an assembly (hub and bearing together). The front units are driven by the CV shafts and use a staked axle nut, the rears are bolt-on hub modules with an ABS tone/encoder built in. Because they’re sealed, care during installation and correct torque are what make them last.

Common tell-tales that a Mazda 3 wheel bearing is on the way out include:

• A humming or growling that rises with road speed and often changes in a long bend
• Play at the wheel when checked at 12 and 6 o’clock
• ABS/traction light if the encoder or sensor signal goes noisy
• Heat at the hub after a drive or uneven “saw-tooth” tyre noise

There’s no set replacement interval, many last 100,000–200,000 km. As part of routine servicing, a quick road test, spin-check on the hoist, and a feel for play or roughness is smart. Also look for torn seals, water ingress from flood driving, or corrosion if the car lives by the coast.

When replacement’s due, go for quality hub assemblies. Replace single-use hardware (axle nut, hub bolts) and torque everything to spec—over-tightening or hammering with a rattle gun can shorten bearing life. A wheel alignment usually isn’t required unless the knuckle is disturbed, but checking it after suspension or hub work is good practice. Don’t put off a noisy bearing, left too long, it can overheat, affect braking assistance from ABS, and chew out tyres.

Popular questions about 2018 Mazda 3 wheel bearings

How long do wheel bearings last on a 2018 Mazda 3?
With normal driving and decent roads, many will run 100,000–200,000 km. Life drops with big potholes, kerb hits, oversized wheels, or poor-quality replacements. Regular checks during services help catch any roughness before it becomes a bigger (and noisier) issue.

What are the signs of a bad wheel bearing on a Mazda 3?
Listen for a speed-dependent hum or growl that changes in sweeping corners, feel for play at the wheel, and watch for ABS or traction warnings. Heat at the hub after a drive is another red flag. Tyre noise can mask the sound, so a mechanic’s road test helps.

Should both front bearings be replaced together?
Not necessarily. Replace the one that’s failed, then assess the other side. If the opposite side shows early signs or the car’s done high kilometres, many owners choose to do them in pairs to save a second visit. Use quality parts and correct torque either way.