Parts for your 1998 Toyota Hilux surf-Gas struts

1998 Toyota Hilux Surf Gas Struts — What They Do and When to Replace Them

Gas struts are relevant and factory-fitted on the 1998 Toyota Hilux Surf for the rear back door (liftgate). Toyota documentation refers to these as the “Back Door Stay Assembly”, listed in the Toyota Electronic Parts Catalog for the 185-series Surf (e.g., KZN185/RZN185/VZN185). The Toyota repair manual for the 1996–2002 Hilux Surf/4Runner family also details removal and installation of the back door stays. Note that the bonnet on this model uses a prop rod from factory, not gas struts.

On the Surf, the gas struts take the weight of the rear hatch, letting it lift smoothly and stay open without drama. Over years of use, the pressurised gas inside the struts slowly loses charge, seals harden, and cold weather can make weak struts barely hold up the door. That’s when the hatch starts drooping or needs a shoulder to keep it up — a good sign it’s time to replace them.

During servicing, it’s smart to give the back door struts a quick check. Open the hatch and see if it rises confidently and holds at full height. If the hatch sags, closes too quickly, or needs a hefty shove to get moving, the struts are tired. Also look for oily residue around the rod seal — that’s a giveaway the internal seal is leaking. Replacement is straightforward: support the hatch safely, pop off the retaining clips, swap the struts one at a time, and click them onto the ball studs. Match the new units to the original length and force rating (often stamped on the strut body). Genuine Toyota parts are catalogued as Back Door Stay Assemblies (example LH/RH part families commonly cited for the 185-series include 68960-xxxxx and 68950-xxxxx), and reputable aftermarket equivalents from brands like Stabilus or Monroe list direct-fit options for the 1996–2002 Surf/4Runner.

• Tell-tale signs they’re due: hatch won’t stay up, slow lift in cool weather, visible oiling on the rod, clunks at the hinge end.
• Good practice: replace in pairs to keep lift balanced, don’t grease the shiny rod, keep the sockets clean, tighten mounting hardware to the manufacturer’s spec.
• Safety tip: always prop the hatch securely while swapping struts — a broom handle isn’t glamorous, but it saves headaches.

Owners keen on convenience sometimes retrofit bonnet struts, but that’s aftermarket — the factory setup is a simple prop rod. For everyday use, fresh rear gas struts make the Surf feel newer, safer, and a lot less likely to thump someone’s head on a windy day.

• Where are the gas struts on a 1998 Hilux Surf, and are they factory?
  The factory gas struts are on the rear back door (liftgate). Toyota lists them as Back Door Stay Assemblies for the 185-series Surf. The bonnet uses a prop rod from factory.
• How often should back door struts be replaced?
  There’s no fixed interval — replace when performance drops. If the hatch won’t hold up, struggles in cold weather, or shows oil around the rod seal, fit new struts (ideally as a pair).
• Can bonnet gas struts be fitted to the 1998 Surf?
  Yes, but it’s aftermarket. Kits exist to replace the bonnet prop rod with gas struts. Choose a Surf/4Runner 185-series-specific kit and follow the supplied mounting instructions.