Parts for your 2005 Mazda 3-Centre bearing

2005 Mazda 3 centre-bearing — is it actually a thing?

Short answer: a conventional centre-bearing isn’t used on the 2005 Mazda 3 (BK series). The official Mazda BK-series Workshop Manual describes a transverse, front-wheel-drive layout with two front drive shafts and, on the right-hand side, an intermediate shaft supported by a bracket-mounted bearing. There’s no propeller shaft and no centre support bearing listed anywhere in the Driveline/Axle section. The Mazda Electronic Parts Catalog (BK) likewise shows no prop shaft or centre support bearing on this model. In automotive service literature, a “centre-bearing” is the support bearing for a two-piece propeller shaft in rear- or all-wheel-drive vehicles, which simply doesn’t apply to a front-drive Mazda 3.

Why it’s not used: the BK Mazda 3’s engine sits sideways and drives the front wheels via CV half-shafts. Because there’s no long propeller shaft running down the car, there’s nothing for a centre support bearing to hold up. Instead, Mazda fits an intermediate (jack) shaft on the right-hand side with its own sealed support bearing and bracket. That bearing’s job is to stabilise the longer right-hand side of the driveline and help control torque steer, but it’s not a “centre-bearing” in the prop-shaft sense.

If someone’s told there’s a “centre-bearing” issue on a 2005 Mazda 3, what they probably mean is the right-hand intermediate shaft support bearing, or they’re chasing noise or vibration from another nearby component. Common suspects include:

• Right-hand intermediate shaft support bearing (also called the axle carrier bearing)
• Inner or outer CV joints
• Front hub/wheel bearings
• Engine and transmission mounts

There’s no scheduled servicing for a centre-bearing on this car because it isn’t fitted. The intermediate shaft support bearing is sealed, it’s inspected for play, roughness or rumble and replaced if worn. Replacement generally involves removing the right-hand drive shaft and intermediate shaft, unbolting the bearing bracket from the block, and pressing the bearing off/on with the correct tooling. A quality replacement and correct installation (including new hardware where specified and proper axle nut procedure) goes a long way to keeping things quiet and smooth. If there’s doubt whether the noise is that bearing or, say, a wheel bearing or inner CV, a proper road test and stethoscope check on a hoist is the way to go.

Technical sources referenced: Mazda 3 (BK) Workshop Manual, Driveline/Axle — Front Drive Shaft and Intermediate Shaft (2004–2009), Mazda BK Electronic Parts Catalog (no propeller shaft or centre support bearing listed for FWD models), standard automotive service definitions for centre support bearings relating to multi-piece propeller shafts.

Popular questions about a 2005 Mazda 3 “centre-bearing”

Does a 2005 Mazda 3 have a centre-bearing?
No. The BK Mazda 3 is front-wheel drive and doesn’t use a propeller shaft or a centre support bearing. If you’ve been told there’s a centre-bearing issue, it’s likely a mix-up with the right-hand intermediate shaft support bearing.

What’s the bearing on the right-hand side of the axle called, and can it be replaced?
That’s the intermediate shaft support bearing (often called a carrier bearing for the axle). It’s a sealed bearing supported by a bracket on the engine block. It can be replaced when noisy or loose, typically with the shaft removed and the bearing pressed off/on using the correct tools.

What could cause a vibration that seems like a bad centre-bearing on a Mazda 3?
On this model, common culprits are a worn right-hand intermediate shaft bearing, a tired inner CV joint, a failing front hub bearing, or soft engine/trans mounts. A technician can isolate the source with a road test and on-hoist inspection.