Parts for your 2018 Mazda 3-Centre bearing

2018 Mazda 3 centre-bearing — what’s actually fitted?

For the 2018 Mazda 3 (BN series), a centre-bearing isn’t used or relevant. The model is front‑wheel drive only and doesn’t have a rear propeller/tail shaft, so there’s no need for a centre support bearing — the “centre-bearing” most Aussies and Kiwis think of on utes and rear‑drive wagons. This isn’t just semantics, it’s how the car is built.

Technical sources back this up: the Mazda 3 (BM/BN, 2014–2018) Workshop Manual covers a transaxle with two front drive shafts and, on the right-hand side, an intermediate shaft supported by a bracket and bearing on the engine block. There’s no propeller shaft section and no centre support bearing service procedure because the car doesn’t use one. The Mazda Electronic Parts Catalogue for BM/BN lists front drive shafts and an intermediate shaft bearing/bracket, but no propeller shaft or centre-bearing assembly. General repair guides such as the Haynes manual for Mazda 3 (2014–2018) also describe only FWD layouts with CV half‑shafts up front.

Why it’s not used on a 2018 Mazda 3 comes down to layout. A centre-bearing lives on long, multi‑piece prop shafts in rear‑ or all‑wheel drive vehicles to support the shaft mid‑span. The Mazda 3’s transverse engine and transaxle send drive directly to the front wheels via two short half‑shafts. There’s no long shaft running down the car that would need a centre support.

What can be mistaken for a “centre-bearing” is the right‑hand intermediate shaft’s support bearing (often called a carrier bearing). That unit’s job is to steady the longer RH shaft and keep torque steer in check, but it’s mounted to the engine block, not under the car, and it isn’t a prop‑shaft centre-bearing.

Owners chasing vibrations that feel like a crook tailshaft bearing should instead check:

• RH intermediate shaft support bearing for play, roughness or bracket looseness
• Inner CV joints for shudder under load and outer CVs for clicking on turns
• Front wheel bearings, engine/gearbox mounts, and tyre balance/condition

Good maintenance on a 2018 Mazda 3 means inspecting CV boots and the RH carrier bearing at each service (about every 10–15,000 km), road‑testing for humming or shudder on acceleration, and rectifying any split boots early to save the joints. If the RH support bearing is noisy or loose, many workshops replace the intermediate shaft assembly rather than pressing a bearing alone, following Mazda procedures and torque specs from the workshop manual.

Does a 2018 Mazda 3 have a centre-bearing?

No. It’s a front‑wheel drive car with no rear prop shaft, so there’s no centre support bearing. The only similar item is the right‑hand intermediate shaft’s support (carrier) bearing mounted to the engine block.

What causes vibrations that feel like a bad centre-bearing on a Mazda 3?

Common culprits are a worn RH intermediate shaft support bearing, tired inner CV joints, front wheel bearings, out‑of‑balance or cupped tyres, or soft engine/gearbox mounts. A road test under light throttle and again under load helps pinpoint which part complains.

How often should driveline bearings be checked on a 2018 Mazda 3?

At every regular service (roughly 10–15,000 km), inspect CV boots for splits, feel for play in the RH carrier bearing, and listen for humming or vibration on a test drive. Replace any noisy or loose components promptly to prevent knock‑on damage.