Troopy Sound Deadening: How to Quiet Your 70 Series LandCruiser
The 78 Troopy is one of the loudest cabins in the 70 Series range. The wide flat body panels resonate, the cargo area amplifies what enters through poor door seals, and the factory pinch-weld door rubber lets wind and dust into the cabin at every highway speed. Sound deadening is the single most measurable comfort upgrade on a touring Troopy build.
This guide covers what to do, what to use and where to apply it.
Shop Soundproofing Door Seal Kit
1. The Soundproofing Door Seal Kit First
Before any deadening mat goes on, replace the factory pinch-weld door seal with the 70 Series Store Soundproofing Door Seal Kit. The factory rubber does not form an airtight closure between door and body, and as it ages the gap grows. The kit replaces the rubber with a bulb-style seal that compresses fully on closure. Independent testing shows up to 3.5 dB reduction at 110 km/h plus dramatic dust ingress reduction.
2. Sound Deadening Mat Application
Quality sound deadening mat (Dynamat, Car Builders, Stinger) at 50 mil thickness covers the panels that resonate most. Apply 12 metres total across: cargo floor (4 sheets), rear quarters left and right (2 sheets each), inside the rear barn doors (1 sheet each), front door cards (1 sheet each). Roll firmly to ensure full adhesion - bubbles or lifted edges reduce effectiveness.
3. Tools and Time
Tools required: utility knife, panel removal tool (or a thin flat screwdriver with tape over the tip), J-roller or sound deadening roller, lint-free rag, and isopropyl alcohol to clean panels before adhesion. A long Saturday with the Troopy cargo area empty is enough time. Removing the cargo area carpet is harder than the mat work and worth doing properly.
4. Best Done Before Interior Fitout
Sound deadening is most efficient before any drawer system, bed platform or fitout goes in. The cargo area is open, every panel is accessible, and the work takes half the time it would take later. Retrofitting around an existing fitout means working through tight spaces around drawer cavities and under bed platforms, which doubles the install time and reduces coverage quality.
5. Measurable Results
With the door seal kit and 12 m of mat applied correctly, expect 3 to 5 dB reduction at 110 km/h. The reduction is most noticeable in the rear cargo area (where the bed platform sits) and on long-distance highway sections. Dust ingress is dramatically reduced - most owners report essentially dust-free cabin conditions for extended outback trips like Cape York and the Simpson Desert.
Frequently Asked Questions
How much sound deadening does a Troopy need?
Around 12 metres of quality sound deadening mat plus the 70 Series Store Soundproofing Door Seal Kit. Total material cost $400 to $700.
How much noise reduction can I expect?
3 to 5 dB at 110 km/h with the door seal kit and 12 m of mat correctly applied. Most noticeable in the rear cargo area where the bed platform sits.
Should I sound deaden before or after the interior fitout?
Before. The cargo area is open and every panel is accessible. Retrofitting around an existing fitout doubles the install time and reduces coverage quality.
Does the Soundproofing Door Seal Kit fit the new 2.8L Troopy?
Yes. The kit fits 78 Troopies from 1999 through to current production including the 2024 facelift. Door geometry has been consistent across the 78 production run.
