Fifthpro
02-02-2007, 11:17 PM
OK, this post is open for tech info suggestions based on Model.
Here on the east coast we have the opportunity to get into some pretty deep water fording situations. What steps have you taken to prevent from being "dead in the water" (pun intended).
Do not let yourself get into this situation without some serious though........
(Yes, I will stop with the LR pics soon enough but this one just rocks! The second one is a Jeep)
http://i66.photobucket.com/albums/h245/Tomahawk_Jeep/LRDeepWaterCrossing.jpghttp://i66.photobucket.com/albums/h245/Tomahawk_Jeep/jeep13watercrossing.jpg
Prior to water crossing you should consider the depth of the water and the capabilities of your vehicle. It is suggested that you pre-rig your vehicle with recovery snatch straps to the front and rear recovery points. This will allow you to be assisted quicker and my save your vehicle from extensive damage. At a minimum you should ensure that you have quick access to your recovery gear.
The first thing to do before any unfamiliar water crossing is to walk it. If you cannot walk it you cannot cross it. If the water is flowing too quickly to safely walk the crossing, then it cannot be driven across. When walking your water crossings its best to walk in the intended wheel tracks to find if there are any hidden rocks or potholes, as well as for checking the depth.
Vehicle Preparation
When you walk the crossing you are actually starting your vehicle preparation. You are giving the axles, differentials and gearbox time to cool down while you find your line across the water.
Differential Breathers
When a hot axle hits cold water it cools rapidly. This has the effect of lowering the air pressure inside the axle and the diff housing, causing air to be drawn in via the diff breathers. Extending your diff breathers higher up the chassis with the aid of plastic tubing is a "must do" for properly prepared vehicles. However, it is no guarantee that water will not enter your diff. The sudden reduction in air pressure inside your diff can still cause water to be drawn in via your axle seals if the diff breathers do not equalize the pressure quick enough. This is why its still necessary to allow the vehicle time to cool down, even when extended differential breathers are fitted.
Air Intake
Water and engines do not mix very well, and when they do it almost always results in bent pistons, valves and crankshaft commonly called "hydro-locking". The positioning of the air intake is critical to how well a vehicle can handle a crossing. NEVER attempt a water crossing where the water depth is above the air intake height. If you intend doing regular water crossings, its a good idea to fit a snorkel as it raises the air intake to your roofline. It doesn't mean you can use your Jeep as a submarine!
Engine Bay Protection
Placing a tarp across the front of the vehicle minimizes water entering the engine bay by creating a bow wave, provided forward momentum is maintained. The result is less water for the radiator fan to spray over the ignition system, less chance of water entering the air intake and less likely for the fan to propel its way up to and through the radiator. Some vehicles (depending on the year it was made) have the distributor to worry about. Water in the ignition system usually results in a stalled engine and not actual engine damage, though this is of little comfort when you find yourself stuck in the middle of a crossing. Depending on the water depth, its advisable to climb out of your window rather than open the door and flood your carpets. To minimize stalling from a wet ignition, it’s a good idea to spray all the ignition system with water repellent beforehand. Other steps can be taken to provide protection to the distributor by covering it with rubber sheets with zip ties or using neoprene. Another technique is to use RTV on the seal in an attempt to keep water out.
Engine Cooling Fan
Some drivers replace their clutch driven fan with an electric fan with a switch so it can be turned off to prevent the fan from spraying water all over the engine compartment and reducing the potential damage that it can cause. Other folks will dissconnect the fan belt to prevent this.
Driving Technique
With a mental picture of your route, and all your vehicle preparation done, its time to start the crossing. Before you enter the water, remember to take off your seat belt and wind down your window.
Using low range second gear at 1500-2000 rpm (for most vehicles) creates the right bow wave. It’s important to get the speed just right as too fast will send water everywhere while too slow may flood the engine bay. If you do strike problems avoid using the clutch as this may allow water to get between the friction plate and the flywheel, resulting in limited drive.
If the wheels start to slip, its important not to over-rev the engine but back-off the accelerator and hope the wheels regain traction. Excessive wheel-spin will not help.
If the engine stalls, put the vehicle in neutral without using the clutch and attempt to restart. If luck is on your side the engine will fire up. Now is not a good time to wish you had already disconnected the fan belt, as your engine bay will be flooded. It’s normally best to use 1st gear low range and with a minimum of clutch usage, try and extricate yourself from this predicament.
Maintenance after Water-crossings
Any crossing at axle depth or deeper necessitates a checking of the diff oil for water contamination. Having an extended diff breather is not a 100% guarantee of waterproof and any crossing above your axles without extended cliff breathers should mean a mandatory inspection.
Checking your diffs for water contamination. Water is heavier than oil, it will collect at the lowest point in the diff. After allowing time for your vehicle to cool, suck a small amount of the diff oil into a glass. If you're unlucky enough to have water present, the diff oil should be drained. Milky colored oil also indicates water is present and should also be changed.
Its not only diffs than can have water contamination, but also your gearbox, transfer case and engine oil. However, it is usually only when a vehicle is stationary in deep water that these components are contaminated.
Amongst other items to check are electric winches. These components may not be used for extended periods and when they're needed you may find they have seized up. If the winch has been submerged in water it is advisable to strip it and grease it accordingly. A quick operation of it after a crossing may prove it still works, but you may find out when it seizes that you washed all the grease out 6 months ago!
A water crossing is something that should not be taken too lightly as it has the potential to do expensive engine and drive-train damage. However, with the right vehicle preparation and post crossing maintenance, you can continue your forward mobility in the most austere conditions.
Here on the east coast we have the opportunity to get into some pretty deep water fording situations. What steps have you taken to prevent from being "dead in the water" (pun intended).
Do not let yourself get into this situation without some serious though........
(Yes, I will stop with the LR pics soon enough but this one just rocks! The second one is a Jeep)
http://i66.photobucket.com/albums/h245/Tomahawk_Jeep/LRDeepWaterCrossing.jpghttp://i66.photobucket.com/albums/h245/Tomahawk_Jeep/jeep13watercrossing.jpg
Prior to water crossing you should consider the depth of the water and the capabilities of your vehicle. It is suggested that you pre-rig your vehicle with recovery snatch straps to the front and rear recovery points. This will allow you to be assisted quicker and my save your vehicle from extensive damage. At a minimum you should ensure that you have quick access to your recovery gear.
The first thing to do before any unfamiliar water crossing is to walk it. If you cannot walk it you cannot cross it. If the water is flowing too quickly to safely walk the crossing, then it cannot be driven across. When walking your water crossings its best to walk in the intended wheel tracks to find if there are any hidden rocks or potholes, as well as for checking the depth.
Vehicle Preparation
When you walk the crossing you are actually starting your vehicle preparation. You are giving the axles, differentials and gearbox time to cool down while you find your line across the water.
Differential Breathers
When a hot axle hits cold water it cools rapidly. This has the effect of lowering the air pressure inside the axle and the diff housing, causing air to be drawn in via the diff breathers. Extending your diff breathers higher up the chassis with the aid of plastic tubing is a "must do" for properly prepared vehicles. However, it is no guarantee that water will not enter your diff. The sudden reduction in air pressure inside your diff can still cause water to be drawn in via your axle seals if the diff breathers do not equalize the pressure quick enough. This is why its still necessary to allow the vehicle time to cool down, even when extended differential breathers are fitted.
Air Intake
Water and engines do not mix very well, and when they do it almost always results in bent pistons, valves and crankshaft commonly called "hydro-locking". The positioning of the air intake is critical to how well a vehicle can handle a crossing. NEVER attempt a water crossing where the water depth is above the air intake height. If you intend doing regular water crossings, its a good idea to fit a snorkel as it raises the air intake to your roofline. It doesn't mean you can use your Jeep as a submarine!
Engine Bay Protection
Placing a tarp across the front of the vehicle minimizes water entering the engine bay by creating a bow wave, provided forward momentum is maintained. The result is less water for the radiator fan to spray over the ignition system, less chance of water entering the air intake and less likely for the fan to propel its way up to and through the radiator. Some vehicles (depending on the year it was made) have the distributor to worry about. Water in the ignition system usually results in a stalled engine and not actual engine damage, though this is of little comfort when you find yourself stuck in the middle of a crossing. Depending on the water depth, its advisable to climb out of your window rather than open the door and flood your carpets. To minimize stalling from a wet ignition, it’s a good idea to spray all the ignition system with water repellent beforehand. Other steps can be taken to provide protection to the distributor by covering it with rubber sheets with zip ties or using neoprene. Another technique is to use RTV on the seal in an attempt to keep water out.
Engine Cooling Fan
Some drivers replace their clutch driven fan with an electric fan with a switch so it can be turned off to prevent the fan from spraying water all over the engine compartment and reducing the potential damage that it can cause. Other folks will dissconnect the fan belt to prevent this.
Driving Technique
With a mental picture of your route, and all your vehicle preparation done, its time to start the crossing. Before you enter the water, remember to take off your seat belt and wind down your window.
Using low range second gear at 1500-2000 rpm (for most vehicles) creates the right bow wave. It’s important to get the speed just right as too fast will send water everywhere while too slow may flood the engine bay. If you do strike problems avoid using the clutch as this may allow water to get between the friction plate and the flywheel, resulting in limited drive.
If the wheels start to slip, its important not to over-rev the engine but back-off the accelerator and hope the wheels regain traction. Excessive wheel-spin will not help.
If the engine stalls, put the vehicle in neutral without using the clutch and attempt to restart. If luck is on your side the engine will fire up. Now is not a good time to wish you had already disconnected the fan belt, as your engine bay will be flooded. It’s normally best to use 1st gear low range and with a minimum of clutch usage, try and extricate yourself from this predicament.
Maintenance after Water-crossings
Any crossing at axle depth or deeper necessitates a checking of the diff oil for water contamination. Having an extended diff breather is not a 100% guarantee of waterproof and any crossing above your axles without extended cliff breathers should mean a mandatory inspection.
Checking your diffs for water contamination. Water is heavier than oil, it will collect at the lowest point in the diff. After allowing time for your vehicle to cool, suck a small amount of the diff oil into a glass. If you're unlucky enough to have water present, the diff oil should be drained. Milky colored oil also indicates water is present and should also be changed.
Its not only diffs than can have water contamination, but also your gearbox, transfer case and engine oil. However, it is usually only when a vehicle is stationary in deep water that these components are contaminated.
Amongst other items to check are electric winches. These components may not be used for extended periods and when they're needed you may find they have seized up. If the winch has been submerged in water it is advisable to strip it and grease it accordingly. A quick operation of it after a crossing may prove it still works, but you may find out when it seizes that you washed all the grease out 6 months ago!
A water crossing is something that should not be taken too lightly as it has the potential to do expensive engine and drive-train damage. However, with the right vehicle preparation and post crossing maintenance, you can continue your forward mobility in the most austere conditions.