Water crossings can be an exciting part of 4-wheeling but can be dangerous to attempt and expensive if things go wrong. For whatever reason you decide to cross a river in your 4×4, consider these tips to help make your experience safe and positive.
The very first thing the smart offroad enthusiast should do is to get out of the vehicle and assess the crossing. Simply looking at the water is not an effective way to properly determine its depth. If you don’t know how deep the water is, walk through it to determine its approximate depth. If you can’t touch the bottom, there’s a good chance your vehicle won’t make it without being submerged. It’s also important to determine how firm the bottom is. If it’s rocky and hard it should be ok to cross, but if it’s muddy or sandy it will be a lot more difficult to cross. The last thing you want is to be stuck in the middle of the river so always be 100% sure before attempting a river crossing. While in the water, also look for large obstacles that may get in the way. It’s also important to take note of how fast the current is moving. Fast moving water can end in disaster so if it’s too fast, don’t risk it.
Now it’s essentially to prepare your 4×4 for the crossing. If the water is higher than bumper height, don’t attempt a crossing without certain aftermarket parts such as a snorkel, and make sure there are no loose parts on the vehicle. One common problem encountered during water crossings are usually caused by the engine’s fan entering the water. When this happens, the fan can spray water throughout the engine, causing ignition systems to stop working. The fan can also bend forward and remove the radiator. To avoid these problems, you can either remove the fan belt or adjust it so that it has very little tension, as long as you don’t drive very far. A lot of modern 4×4’s will have couplings on the fan which allows them to free spin when the engine or surrounding air temperature is low, which can be sufficient to handle water. It’s also recommended to let your car cool down before a crossing, which will help prevent additional water to be sucked in through the differentials.
In case you get stuck, make sure that you have recovery gear on hand in case you get stuck. If you’re by yourself, it’s necessary to have a winch attached to your bumper. It’s important to recover your vehicle quickly in case it begins to sink, so make sure to have a plan of recovery before you get into the water.
Another tip you can take note of that some offroad enthusiasts will use it to make use of a tarp over the front of your vehicle. This can help minimize the amount of water entering your engine and can help push water to the side of the vehicle, instead of inside it. This will help prevent the motor from seizing. While not necessary, you can also help prevent water from entering important components by adding a pipe extension to your exhaust above the water level.
When entering the water, keep your speed low, between 2-6 miles an hour (depending on how deep the water is). Going too fast can cause water to go everywhere (including your engine bay) and can make you lose traction. However if you go too slow, you may not have enough momentum so it’s important to find a nice balance which will usually depend on how deep you are and what kind of bottom you’re driving on. Your speed should be enough to maintain a good “bow wave” which will provide a lower water level for the rest of the car. Try to avoid changing gears or stopping as this could cause the clutch to fill with water. If you over-rev the engine, you risk damaging the radiator or overheating the motor. A good rpm range would be between 2000-2500rpms, depending on the vehicle.
If you’re attempting a water crossing with multiple vehicles (always bring a buddy!) make sure to only have one 4×4 cross at a time in case someone gets stuck. Once you’re out of the water, clean off any mud that may be stuck to important components (brakes, rotors, intakes, etc) and reattach any parts you may have removed. It’s also not a bad idea to check your differentials, gearbox, and transfer case for signs of water contamination. After a water crossing, it’s always helpful to take your vehicle in to an auto service center or offroad shop to get 4×4 service.