Comprehensive Undercarriage Protection and Corrosion Prevention (Jan 2026)

Ensure the vehicle has been stationary for at least 3 hours. Spraying cold water on a hot exhaust manifold or brake rotors can cause thermal shock and warping. Position the vehicle on a concrete pad with adequate drainage; avoid working on grass as the degreasers and salt runoff will kill vegetation.

Using a trolley jack, lift the vehicle to its maximum safe height and secure it with four heavy-duty jack stands. Never work under a vehicle supported only by a jack. Remove the wheels to provide better access to the wheel arches and suspension components, which are primary catchments for salt and mud.

Use a torch to inspect the chassis rails, fuel tank straps, and suspension seats. Manually remove large clumps of mud, sticks, or 'spinifex' grass that may have accumulated. Spinifex is a particular fire hazard in Australian summer conditions if trapped near the catalytic converter.

Prepare your cleaning solutions. For heavy red dust, mix your alkaline degreaser at a 1:5 ratio in a pump sprayer. For salt neutralisation, follow the manufacturer's ratio (usually 15ml per litre of water). Having these ready ensures a continuous workflow without stopping to mix chemicals mid-process.

Perform a thorough rinse of the entire undercarriage using only water. Start from the front and work backwards, focusing on the tops of the chassis rails where red dust settles. Spend at least 15 minutes on this stage to hydrate and loosen hardened mud and salt crystals.

Apply your alkaline degreaser liberally to all metal surfaces, suspension components, and the exterior of the engine/gearbox. Avoid direct spray onto electrical connectors or the alternator. Allow the product to dwell for 8-10 minutes, but do not let it dry, as Australian heat can cause chemical etching.

Using your nylon brushes, scrub the areas where grease and dust have formed a 'paste'. Pay close attention to the differential housings, control arm bushings, and the areas behind the wheel liners. Agitation is key to removing the microscopic film that pressure washing alone misses.

Rinse the degreaser away, ensuring the water runs clear. Use an underbody lance to reach into the 'C-channels' of the frame. If the water coming out of the frame holes is still brown or red, continue rinsing until it is perfectly clear.

Apply the salt neutraliser using a foam cannon or pump sprayer. Unlike degreaser, this chemical must penetrate the pores of the metal. Leave it for the recommended time (usually 5 minutes). This step is non-negotiable for vehicles driven near the coast or on K'gari (Fraser Island).

Perform a final rinse. To ensure the protective coatings adhere properly, the undercarriage must be dry. Use a leaf blower or compressed air to blow water out of bolt holes, crevices, and electrical plugs. Ideally, leave the vehicle in the sun for 2 hours to ensure total moisture evaporation.

Insert the 360-degree wand of your Lanolin or cavity wax spray into the factory drainage holes of the chassis. Spray as you slowly retract the wand. This coats the inside of the rails where rust usually starts unseen. Lanolin is preferred in Australia as it doesn't dry out or crack in extreme heat.

Apply a thin, even coat of chassis protection to the exterior of the frame rails and floor pans. Avoid the exhaust system, driveshafts (which can be thrown out of balance by heavy coatings), and brake components. This creates a physical shield against rock chips and sandblasting.

Apply a silicone-free rubber protectant to CV boots, suspension bushings, and brake lines. This prevents the rubber from 'drying out' and cracking under the intense UV radiation and heat reflected from Australian roads.

Reinstall the wheels and torque the nuts to factory specifications. Once the vehicle is back on the ground, do a final walk-around to ensure no over-spray has landed on the exterior paintwork. Wipe any excess Lanolin off visible trim areas immediately.