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Steps For Waterproofing Your Off-Road Ride

Steps For Waterproofing Your Off-Road Ride

Any off-roader will know that getting into water is inevitable, and although taking a dive with your 4×4 may seem like great fun, having a waterproof ride is essential. Water gets into electronics and cylinders pretty quickly, and the damage can be irreparable.

If diving is your only option, you should at least come prepared. Here are the steps for waterproofing your off-road ride.

The most important things you need to protect from water include the engine, the differentials, the transmission system, the electronics and the interior. The best way to do this is to:

  • Attach a snorkel
  • Install diff-breather extension tubes
  • Install gearbox and transfer case extension tubes
  • Install a waterproof fuse/relay block panel
  • Maintain door seals

Some of these steps can be quite challenging and expensive, but they are definitely worth the effort. The section below discusses these waterproofing steps in more detail, with some advice to keep you safe and dry!


If the engine of your off-roader ingests water, you will definitely be left stranded. In a worst-case scenario, you will end up with damage to your car’s engine due to water being compressed in the engines pistons. This is called hydraulic lock and will in the least cost you an expensive tow back to civilization.

Your all-roader probably comes standard with an air intake and filter that is positioned at about headlight height. Even though all vehicles come with a manufacturer’s specified maximum wading depth, these measurements do not account for any spillover from waves caused by the cars movement. Additionally, driving through deep water usually requires a bit of speed to retain grip in muddy terrain, and speed equals waves and splash.

Enters the snorkel. This extension of your cars air intake will allow the engine to suck in clean, dry air while the car is driving through deep water. It is positioned at roof height to prevent water splashing over the bonnet and entering the snorkel.

It is important to install a good quality snorkel with quality attachments, to prevent any mishaps in the field. Important qualities to look out for in a snorkel include:

  • Air tight fittings to prevent leaks
  • UV stable material to avoid cracking and perishing
  • Design that allows optimal air intake by the engine

Practical motoring recommends the following snorkel brands: Dobinsons, Airtec, Airflow and Sherpa.

Diff-breather extension tubes

While driving, the diff of a car will heat up which will result in a pressure build-up inside the casing. When the diff is submerged in cold water, it will cool down and the pressure will decrease which will result in a vacuum that can suck in water. The diff of any 4×4 comes standard with a one-way valve pressure release valve, or breather to prevent this, but it does not always do the trick. Especially when the diff is cooled very fast.

Replacing the one-way valve with a diff breather extension tube, will prevent the vacuum from forming and water being sucked into the diff. These are fitted with an inlet high on the engine bay, and along with the waterproof filter, will prevent water from entering the diff compartment.

You can buy fitting kits that allow you to fit these extension tubes yourself, or alternatively you can have your car fitted by your 4×4 specialist.

Gearbox and transfer case extension tubes

These work in basically the same way as the diff-breather extension tubes. Due to variations in pressure, a vacuum in the gearbox and transfer cases can result in water uptake. They also come equipped with a one-way valve, but these may not be waterproof.

Fitting breather extension tubes for your gearbox and transfer case will ensure they stay water free, and your 4×4 can keep on moving!

Several brands of extension tubes are available on the market, the most popular being Piranha Off-road, ARB, Ironman 4×4, Opposite Lock and Harrop Engineering.

Waterproof fuse & relay block panel

Electronics are particularly difficult to insulate, and relays typically do not fare well when wet. You can opt for simply replacing your normal relays with waterproof relays, but the best option would probably be to install a waterproof fuse and relay block panel.

These come with standard or waterproof relays and fuse protection for each circuit. It is installed under the hood and is universal, so would fit any vehicle. Since it comes as unit, any after-market electrical additions are easy to install yourself.

You can buy DIY kits for roughly $200 and they are available on Amazon.

Maintain door seals

This almost goes without saying – but waterproofing your cars doors saves you a lot of pain and effort in drying out your car after a water adventure. As an addition, if you keep the inside of your car dry, the interior electronics are also protected from direct water contact and excessive moisture.

Generally, as long as you keep moving in water, the seals of your 4×4 should hold, but we all know that slowing down and stopping is sometimes inevitable. For extra protection, it is a good idea to make sure your seals are always well maintained to prevent cracking.

You can do this by keeping them clean of dirt and grime and by cleaning and drying them after a muddy submersion. Several treatment products, such as silicone spray or WD40, are also available on the market that you can use to moisturize and protect the rubber, which will extend the life of your door seals.

Some tips on driving through deep water

Waterproofing your off-roader is only one of the steps you can take to get through a water source dry. There are several things you need to consider before taking the plunge, which will ensure you get through safely.

  • How deep is the water? It may be a good option to either confer with someone, who knows the route, on the water depth and capabilities needed to make the crossing. Alternatively, you can try to wade in if the water is safe, to assess the depth yourself.
  • What are the best entry and exit points? Taking the wrong angle to start with can end up with you being stuck in the water. The last thing you want to do is drive around in the water to find the best exit point!

Consider the steepness of the entry and exit points compared to the clearance of your car, while choosing the most direct path through.

  • Test the current and flow of a river before entering with your car. A stronger current may mean less slippery riverbed as slow moving water gathers sediment. Be careful though, a very strong current may drag you along and can tip your car over.
  • Walk the water path and check for any obstacles such as large rocks or holes. You can even consider staking out the route beforehand to ensure you follow the safest route.
  • Once you have decided on a route, put the car into automatic 4WD (low range) and leave it in drive to maintain a steady pace. For manual transmissions, second gear is better than first, for a steady speed.
  • When you hit the water, you may have to increase speed as the water offers resistance to the car’s movement. Maintain a steady speed that prevents too much splashing over the bonnet.
  • Once you have safely exited the water, try to keep the car on a slight incline to allow water to drain from the undercarriage. Then perform a manual check to remove any debris stuck to the underside of the car, before you proceed on your journey.

Waterproofing your 4×4 may cost you some money and time, but the pleasure of going on a semi-aquatic adventure with no doubts about your off-roader’s abilities, is priceless!