Parts for your 2020 Holden Commodore-Bump stops

2020 Holden Commodore bump-stops

Based on OEM Holden/GM service information for the ZB Commodore (Opel Insignia B platform) and the Holden Electronic Parts Catalogue, the 2020 Holden Commodore is fitted with bump-stops (also called jounce bumpers) on both the front MacPherson struts and the rear shock absorbers. Aftermarket damper catalogues also list dedicated strut protection kits (dust boot + bump-stop) for this model, reinforcing that bump-stops are standard equipment, not an optional extra.

On this Commodore, bump-stops act like a small, progressive secondary spring. They step in right at the end of suspension travel to prevent harsh metal-to-metal bottoming, protect the strut and shock internals, and keep the car composed over big hits, sharp driveway entries, corrugations, or when laden with passengers and gear. They also help reduce noise and vibration through the body, which is a big part of the refined ride these cars are known for.

Because bump-stops live on the moving damper rod and cop a lot of dust, water, and heat, they’re made from resilient foam or polyurethane. Over time they can perish, crack, or even crumble. Common clues on a ZB Commodore include a dull thud on big bumps, a harsher-than-usual ride at the end of travel, visible tears or missing pieces on the bump-stop, or a torn dust boot letting grit at the damper seal. While a worn bump-stop won’t change ride height, it can accelerate wear of your shocks and struts if the car bottoms out more often.

Good practice is to have the bump-stops inspected whenever the shocks/struts are checked—typically every 40,000–60,000 kilometres or at regular servicing if the car tows, runs heavy loads, or sees rough roads. Replace them in pairs on an axle, and always fit the matching dust boots. If the Commodore is due for new shocks or struts, it’s smart and cost-effective to replace the bump-stops at the same time because the struts are already out.

When replacing, use quality OEM-equivalent parts. Front strut work requires a proper spring compressor and torque-to-spec reassembly, and it’s wise to book a wheel alignment afterward. If the vehicle regularly bottoms out under load, chat with a technician about set-up options—fresh dampers, upgraded bump-stops, or helper solutions—to suit Aussie and Kiwi road conditions without compromising safety or comfort.

• Inspect at service intervals or 40,000–60,000 km
• Replace with shocks/struts or if cracked, missing, or perished
• Always fit dust boots and replace in axle pairs
• Get an alignment after front strut work

Popular questions about 2020 Holden Commodore bump-stops

Do the front and rear of the 2020 Commodore both have bump-stops?
Yes. The front MacPherson struts use internal jounce bumpers under the dust boots, and the rear shock absorbers have their own bump-stops as well. They’re part of the suspension’s final line of defence against bottoming and are included from factory on ZB models.

When should bump-stops be replaced on a ZB Commodore?
They should be inspected at routine services and replaced if cracked, perished, oil-soaked, or missing. Many owners opt to replace bump-stops whenever fitting new shocks or struts—typically somewhere between 60,000 and 120,000 kilometres depending on use. If the car tows, carries heavy loads, or drives on rough roads, expect earlier attention.

Is it OK to drive with damaged bump-stops?
Short trips may be manageable, but it’s not ideal. Without a healthy bump-stop, big hits can bottom the suspension, stressing the shock or strut, bending mounts, and making the ride harsh. It’s best to book replacement soon to protect the rest of the suspension and keep the Commodore comfortable and safe.