Parts for your 2020 Holden Commodore-Steering rack

2020 Holden Commodore steering rack: purpose, care and when to replace

Technical sources confirm the 2020 Holden Commodore (ZB) is fitted with a rack-and-pinion steering rack with electric power assist (EPS). Holden’s MY20 Commodore Owner’s Manual describes Electric Power Steering, GM Global Service Information (ZB Commodore) details a rack-mounted EPS system, and Opel Insignia B/Commodore workshop material plus GM/ACDelco parts catalogues list a complete steering gear (rack) assembly for 2018–2020 models. That makes the steering rack directly relevant for this vehicle.

On this Commodore, the steering rack converts the driver’s steering wheel input into precise movement at the front wheels. Because it’s an electric rack (not hydraulic), there’s no power steering fluid to top up. The electric motor and control module are integrated with the rack, delivering variable assist by speed and steering load for a tidy, confident feel around town and on the open road.

As part of regular servicing, the rack itself is largely maintenance-free, but a workshop should still keep an eye on the bits around it. Practical checks include inspecting rack boots for splits, confirming inner and outer tie-rod play is within spec, checking the rack mounts, verifying alignment, and scanning for EPS fault codes or available software updates. Good alignment and healthy tyres help the rack do its best work and keep tyre wear even.

If a rack is worn or damaged, drivers might notice symptoms such as:

• Knocking or clunking over bumps, or free play around centre
• Heavy or inconsistent steering effort, or a steering warning light
• Uneven or rapid tyre wear, tramlining, or the car pulling to one side

When replacement is needed, a quality OEM-spec steering rack is the go. A proper job on a ZB Commodore includes centring the rack, torquing fasteners to spec, replacing tie rods if required, performing a full four-wheel alignment, and carrying out EPS resets/calibration (including steering angle sensor and any module programming). A final road test confirms on-centre feel and assist are spot-on. With decent roads and regular checks, many racks will go the distance for hundreds of thousands of kilometres.

Sources referenced: Holden MY20 Commodore Owner’s Manual (Electric Power Steering), GM Global Service Information for ZB Commodore (EPS system description), Opel Insignia B/Commodore workshop documentation (rack-and-pinion EPS), and GM/ACDelco parts catalogues listing steering gear assemblies for 2018–2020 models.

Does the 2020 Holden Commodore use a steering rack or a steering box?

It uses a rack-and-pinion steering rack with electric power assist. The EPS motor is mounted to the rack, providing variable assist without hydraulic fluid. This setup delivers precise steering and reduces maintenance compared with older hydraulic systems.

How long should a steering rack last on a 2020 Commodore?

With normal use and regular checks, an electric rack can last for many years and high kilometres. Longevity depends on road conditions, tyre/alignment care, and avoiding impacts like kerb strikes. Any play, noise, warning lights, or uneven tyre wear should prompt an inspection.

Is a wheel alignment needed after replacing the steering rack?

Yes. After any rack or tie-rod work, a full four-wheel alignment is essential, along with EPS resets/calibration and steering angle sensor procedures. Skipping these steps can leave the steering off-centre, cause odd tyre wear, or trigger steering warnings.