Parts for your 2018 Holden Commodore-Rack boots

2018 Holden Commodore rack boots — what they do and when to replace them

Yes — the 2018 Holden Commodore (ZB) uses rack boots. Technical documentation in Holden/GM Global Service Information for the ZB’s electric rack‑and‑pinion steering, along with GM Genuine Parts catalogues and Opel Insignia B (the ZB’s twin) workshop diagrams, all show bellows‑type boots on each end of the steering rack protecting the inner tie rods and rack seals.

On a 2018 Commodore, rack boots (also called steering rack gaiters) are the flexible rubber bellows that seal the ends of the electric power steering rack. Their job is simple but crucial: keep water, mud, and road grit away from the rack bar and inner tie rod joints, while letting the steering move freely lock‑to‑lock. By keeping the grease in and the grime out, they help the rack run quietly, protect the inner joints from premature wear, and fend off corrosion. On the ZB’s electric rack there’s no hydraulic fluid, so a healthy boot should be dry outside and lightly greased inside, if you spot oily residue in a boot, that can point to an internal rack issue that needs attention.

As part of regular servicing, it’s smart to give the boots a close look every 10,000–15,000 kilometres (or at each service). What to watch for:

• Cracks, splits, or perishing in the rubber
• Grease flung onto the lower control arm or inner guard
• Loose, missing, or makeshift clamps (zip ties don’t cut it)
• Water or grit inside the boot when compressed

If a boot is damaged, replace it promptly to avoid chewing out the inner tie rod and steering rack. A proper replacement on the ZB typically involves removing the front wheel, marking the outer tie‑rod end position, separating the tie‑rod end from the knuckle, sliding off the old boot, cleaning the area, then fitting an OEM‑quality boot with new clamps (preferably OE‑style ear clamps). A wheel alignment check is recommended afterwards, because any movement at the tie‑rod end can nudge toe settings.

Quality matters here — go for a boot kit specified for the 2018 Commodore/Insignia B rather than a universal bellows. Technicians will also check the inner joint for play while the boot is off, if there’s looseness or noise on turns, the inner tie rod may need replacing at the same time. Staying on top of rack‑boot condition helps keep steering light, quiet, and roadworthy — and saves dollars by preventing avoidable rack or joint damage.

FAQs

Are rack boots the same as steering rack gaiters on a 2018 Commodore?
Yes. “Rack boots”, “gaiters”, and “bellows” are different names for the same protective rubber sleeves that cover the ends of the steering rack and inner tie rods on the ZB Commodore. They seal out contaminants and retain grease so the rack and joints last longer.

How often should rack boots be checked or replaced?
Have them inspected at every service (roughly every 10,000–15,000 km). Replace at the first sign of cracking, splitting, loose clamps, or contamination inside the boot. Leaving a torn boot can quickly wear out the inner tie rod and compromise roadworthiness.

Can you drive with a torn rack boot?
It’ll still steer, but it’s risky. Grit and water can get in and destroy the inner joint, and you may end up with play, noise, or uneven tyre wear. It’s best to book a replacement ASAP and have the alignment checked once it’s fitted.