THE SAND ASSASSIN™ PRO Underbody Pressure Washer

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The Sand Assassin™ PRO Underbody Pressure Washer

The original Aussie-made underbody roller. Wheel it under, hold the trigger & blast salt, sand, mud & dirt OFF your rails, diffs & every underbody part the drive thru never touches!

The original & only Aussie-made underbody roller: CNC machined & assembled in Brisbane
LIFETIME warranty & every spare part available
3 modes with every jet included: sand, mud & salt
Fits every major washer: 11 adapters, 1,000 to 4,000 PSI
No ramps, no crawling: clean from standing height
4WDs, utes, caravans, boats & trailers: if it has an underbody, it cleans it

Pick the adapter that matches your pressure washer

or 4 payments of $59.98 interest-free

✓ Pays for itself in under 8 uses! Vs the $30+ drive thru: then every wash is Free!

LIFETIME WARRANTY*Brisbane made, backed for as long as you own it. *Tap for terms

FREE shipping Australia-wide on every Sand Assassin PRO
Same-day dispatch on orders before 11am AEST, Monday to Friday
Click & Collect Brisbane · ready in around 2 hours at Geebung HQ

Quick answers

← swipe the questions →

4.8 ★4,800+ reviews

70,000+4WDetail customers

Aussie MadeBuilt in Brisbane

LifetimeWarranty

Industry first

Type your washer. We'll match your adapter.

Like a rego lookup for your pressure washer. Built from thousands of real fitment answers by our Brisbane crew, so you never have to guess.

How to measure your lance extension: twist to unlock & pull it out of the trigger handle, then measure the adapter tip diameter in millimetres

Confirm your fit in under a minuteFollow the two steps shown, then select the closest measurement below & we'll match the adapter:

This tool & its data are the intellectual property of 4WDetail PTY LTD

The FIND MY ADAPTER tool, including its software, fitment logic & underlying compatibility database, is the intellectual property of 4WDetail PTY LTD. The database is an original compilation built from years of in-house fitment verification & records, protected by copyright under Australian law. It also contains uniquely identifiable markers: unauthorised copies can be identified & traced to their source. Reproduction, scraping or adaptation of this tool or its data without written permission is prohibited. 4WDetail PTY LTD reserves all rights, including enforcement. © 2026 4WDetail PTY LTD. All rights reserved.

One tool, every job

3 modes. Every mess. All included.

GEN 3 was re-engineered from the ground up to be 100% modular: swap jet configurations in seconds to match whatever the track threw at your underbody. Every jet & plug comes in the box.

Sand Flood ModeThe two black 65° wide-mouth nozzles flood high-volume water, floating sand & grit out instead of sandblasting it into your brake lines & looms.= the beach weekender

Mud Munching ModeTwo turbo nozzles spin a concentrated pencil jet in a tight cone, thousands of strikes a minute, rattling caked mud & clay off your underbody. Owners report it even shifts small gravel.= bog runs & clay tracks

Salt/ Classic ModeFour white 40° high-pressure nozzles: the all-rounder that rinses dissolved salt off the whole underbody after a Salt Exterminator soak, & handles road grime & general dirt week in, week out.= beach trips & the regular clean

1 · SAND FLOOD Sand Flood Mode: wide-mouth nozzles flooding high-volume water under a 4WD

2 · MUD MUNCHING Mud Munching Mode: turbo nozzles blasting packed mud off the underbody

3 · SALT/ CLASSIC Salt/ Classic Mode: four high-pressure nozzles purging salt from the chassis rails

See the difference

Drive thru wash vs the Sand Assassin PRO

Everyone assumes the drive thru underbody wash does the job. So we put it to the test against the Sand Assassin PRO, on the same 4WD.

The testOne filthy underbody, straight off a big trip.= any trip, any season

The drive thruA commercial underbody wash does its best, at $30 a pass.= money sprayed, sand stays

The Sand Assassin PROThen the roller goes under & shows what was still hiding in the rails.= like the beach ended up on your driveway

What's in the box

14 pieces + your adapter. Nothing else to buy.

Every jet, plug & extension for all three modes comes standard, & the whole system rearranges whatever way works best under your rig.

The Sand Assassin PRO roller
GEN 3, CNC machined in Brisbane

2 straight extensions
Reach right across the underbody

1 × 90° extension
Keeps your wrist straight, not aching at an awkward angle

Your pressure washer adapter
Quick connects straight onto the extension: click, done

2 turbo nozzles
The mud munchers

2 red blanking plugs
Blank off ports to send full pressure to the turbos

4 white 40° nozzles
High pressure, the all-round underbody clean

2 black 65° wide-mouth nozzles
High flow for extremely effective sand flushing

Every piece above is stocked as a spare, so one broken piece never costs you the whole tool.

The original, three generations deep

We don't make toys. We make pro grade tools.

You can't feel quality in a photo. In your hands it's a different story. One owner who'd seen a copy up close put it best: “it just looked and felt cheap... you can tell these were made by someone that cares.” That care is three generations of Brisbane engineering, & it's why this is the only 4 jet underbody washer certified to wear the Australian Made badge. The imports can't touch that: legally or literally.

GEN 1

2020 - 2021

Four fixed jets, no changing them. Proved the idea: the underbody clean without the crawl.

GEN 2

2021 - 2022

Five fixed jets on a mild steel body. It worked, & it taught us exactly what to never build with again.

GEN 3

2022 - Present

Re-engineered from the ground up: CNC machined, 100% modular, protected proprietary design. The original, perfected.

← swipe the generations →

Pro grade vs pretend	Sand Assassin PRO	Cheap imports
Made in	Brisbane: CNC machined & assembled	A generic overseas mould with a new sticker
Australian Made badge	The only 4 jet underbody washer certified to wear it	Legally can't wear it
Fits your washer	11 adapters: every major Aussie brand covered	Quick connect only: most home washers miss out
Configurations	3 swappable modes, every jet in the box	One spray, take it or leave it
When a part wears	Every spare available, from nozzles to axles & even bearings	Bin it & buy again
Warranty	LIFETIME	30 days if you're lucky
Track record	The original · 3 generations deep	Launched last month

Justin assembling an early Sand Assassin by hand

Built by hand firstJustin assembled & tested the early generations himself, on his work bench.

Sand Assassin blueprints and design files

Drawn, tested, redrawnYears of design files behind every jet angle: now a protected proprietary design.

GEN 3 Sand Assassin being CNC machined in Brisbane

CNC machined in BrisbaneGEN 3 is CNC machined & assembled right here in Brisbane. No generic overseas mould, no shortcuts.

The old ways

The hose wets it. The lance misses it. The rust loves it.

Before the Sand Assassin there were four options: pay the drive thru forever, wave a garden hose underneath, sit a sprinkler under there & hope, or crawl under with a lance & cop the spray. All four miss the spots that rust first.

Side by side	Sand Assassin PRO	Drive thru wash	Hose & sprinkler
The water hitting your rails	Your own clean water	Everyone else's salt	Clean, but no punch
Packed sand & mud	Blasted out, gravel too	A surface rinse at best	Barely moves it
Rails, seams & crossmembers	Jets aimed right up at them	Misses most of them	Hit & hope
Water used	Minutes of targeted pressure	Recycled, & you still pay	~1,000L an hour
Your back	You stay on your feet	Comfy, shame about the salt	Crawl, or sit & wait
Cost over the years	Pays for itself fast	$30, every single visit	Free now, rust bill later

The old sprinkler-under-the-4WD trick? That's chemistry working against you. Salt water is an electrolyte: its dissolved chloride ions turn every stone chip & scratch in your chassis paint into a tiny battery, accelerating the electrochemical corrosion eating the metal underneath. A sprinkler pumping ~1,000 litres an hour with no pressure behind it doesn't wash salt off, it re-wets it, keeping that electrolyte working on your exposed chassis for hours. You're not slowing the rust down, you're feeding it.

The Sand Assassin PRO breaks the cycle: your own clean water, real pressure, aimed by you straight at the spots where corrosion starts, in a fraction of the time on a fraction of the water. Soak with Salt Exterminator first & the combo dissolves the ionic salts plain water can't touch, then blasts the lot off the underbody.

Once the salt, mud & grime are actually gone, the rust has nothing left to work with.

Every trip leaves its layer behind: salt, sand, mud & red dirt packed onto the tops of your rails & into every seam & bolt thread, exactly where a hose can't shift it & a lance can't see it. Left there, it traps moisture against your chassis paint & every exposed edge, quietly corroding your 4WD from the outside in. It's why used-4WD buyers crawl underneath with a torch before handing over a cent, & why almost every hard-driven 4WD in the country is hiding rust somewhere.

Jets angled up at the rails
The roller fires up at rails, seams, diffs & crossmembers, sweeping the spots a lance misses.

High-volume flood
Moves kilos of packed sand & mud fast, with any washer from 1,000 to 4,000 PSI.

Built for the combo
Salt Exterminator dissolves what water can't, then Salt/ Classic mode flushes it out.

4WDs · utes · boat trailers · caravans · camper trailers · horse floats · machinery

Trusted by the 4WD community

The gear the 4WD 24-7 crew runs on their own rigs

The crew from 4WD 24-7, the biggest 4WD channel in the world with over a billion minutes watched, run 4WDetail gear on their own rigs. Watch the Sand Assassin PRO go head to head with the old hand wash & the drive thru below!

Sand Assassin PRO · “the 3-in-1 4WD underbody cleaner”

POV · “cleaning without a Sand Assassin PRO”

Drive thru wash · “vs the Sand Assassin PRO”

← swipe the clips →

Got footage of the Sand Assassin flushing a summer of beach out of your chassis? Send it to help@4wdetail.com & we'll feature the best clips.

The drive thru trap

The underbody wash you're paying for is working against you

Most drive thru tunnels run on recycled, contaminated water: the grit, salt & road film rinsed off every car before you, filtered & fired straight back at your 4WD. And their underbody blasting jets have one setting: flat out. That blast doesn't float sand out of your underbody, it rams it upward: over the tops of your chassis rails, across crossmembers, behind body mounts & into cavities no drive thru can ever rinse out.

Your underbody carries more electronics than ever. ABS sensors & their wiring, diff breathers, trailer plugs, parking sensor looms. None of it was designed to cop a point-blank commercial blast. That extreme pressure forces water past seals & into connectors it should never reach, & water in a loom means electrical gremlins that cost serious money to chase.

And you're paying $30 a pass for the damage. At 15 washes a year that's $450 a year, every year: $2,250 over five. Here's the disappointing part: get home, crawl under with a torch, & the sand is still there. Strewn across the TOP of your chassis, packed into the rails, exactly where the drive thru pushed it. Left sitting there, it traps moisture against your chassis: rust, corrosion, chewed paint & electrical faults, all bought & paid for by you.

That's exactly why the Sand Assassin PRO runs three modes instead of one setting: Sand Flood mode to float sand off the rails & out from under the vehicle, Mud Munching mode for the caked-on build-up & Salt/ Classic mode for the corrosion layer. Not every clean-up needs the excessive, damaging power of a commercial drive thru. The right pressure for the job gets the sand, mud & salt OUT instead of UP.

Your driveway. Your water. It pays for itself inside 8 washes, & the lifetime warranty means every wash after that is genuinely free: no more paying at the drive thru, no machine to replace, ever.

Fresh water only
Your hose, your water: no recycled grit & salt fired back at your rig.

3 modes, not one setting
Sand Flood, Mud Munching & Salt/ Classic modes: the right pressure for every job.

Cleans where drive thrus can't
Rotating jets sweep the tops of your rails & crossmembers, pushing sand OUT, not further up.

One machine · Every clean-up · $0 a wash

How to use it

The tried & tested pro detailing method

Minutes in the driveway & you never even bend down. The spray stays under the 4WD, not on you: no crawling on wet concrete, no spray-back in the face, no sore back afterwards.

Applying Salt Exterminator to the underbody

Soak

Coat the underbody with Salt Exterminator as directed & let it dwell. It dissolves the ionic salt & breaks the grip of corrosive mud & red dirt while you set up.

Blast

Fit your adapter, pick your mode & wheel the Sand Assassin under. Hold the trigger, walk slow & watch the sand, salt & mud pour out onto the driveway. No ramps, no crawling, no soaked sleeves.

Applying Chassis Shield to the clean, dry underbody

Seal

Let the underbody dry, then seal it with Chassis Shield. Salt, sand, mud & red dirt rinse off a sealed chassis even easier, so every clean-up from here on gets faster.

← swipe the steps →

THE GOLDEN RULES

Pressure washer: anything 1,000 to 4,000 PSI, electric or petrol
Adapter: quick connects onto the extension, no tools · message us if unsure
Modes: match the jets to the mess: sand, mud, red dirt or salt
Passes: slow & overlapping, front to back
Beach trips: always soak with Salt Exterminator before Salt/ Classic mode
Mud & red dirt: Mud Munching mode to break it off, then a Salt/ Classic mode rinse
Afterwards: let the underbody dry, then seal it with Chassis Shield: salt, sand, mud & red dirt rinse off a sealed chassis even easier next trip

Justin, founder of 4WDetail, with his 4WD

Lifetime Warranty

The first Sand Assassin was built on Justin's work bench: assembled, tested & rebuilt until it earned its name. Three generations on, it's CNC machined & assembled in Brisbane & backed for as long as you own it. If a covered part ever fails, we replace it. If anything else ever lets go, every piece, from nozzles to axles & even bearings, is stocked here in Brisbane & posted at a heavily discounted rate. A copy is landfill the day something cracks. This one you'll still be running in ten years.

BrisbaneMade & machined

GEN 3Three builds deep

LIFETIMEBacked for life

★★★★★ 4,800+ Reviews

*The fine print (it's short)

The GEN 3 lifetime warranty covers the structural integrity of the yellow boom, axles, wheels, the quick connectors attached to the yellow boom, lance extensions & thread damage, for as long as you own it. It doesn't cover accidental damage (like a wheel run over by the vehicle) or wear & tear to the powder coating, wheel bearings or turbo jets, & parts not listed aren't covered. The good news: every part is stocked as a spare, & anything outside the warranty is supplied at a heavily discounted rate, so a broken piece only ever costs you a part. Email help@4wdetail.com with your order number & a photo & we'll sort it. In addition to your Australian Consumer Law rights.

FAQ

Your questions, answered

Reviews

Thousands of real 4WDers. Here's what they reckon.

✦ WHAT REVIEWERS SAY

Reviewers keep landing on the same words: solid, well made, "just the weight of the thing you can tell it's made properly." They say it halves clean-up time, saves crawling on wet concrete, reaches the spots a lance can't, & shifts packed mud, sand, even small gravel. Boat trailers, caravans & earthmoving gear get the same treatment.

Summarised from verified Loox reviews of the Sand Assassin PRO

What buyers add with this