Should I Use 4H Or 4L? - Ridgeback Service Bodies

When to Use 4L (Four-Low): Crawling with Confidence

When it comes to tackling extreme off-road conditions, 4L is the gear that gives you the ultimate control and power. Unlike 4H, which is suited for maintaining moderate speeds, 4L is all about maximising torque and minimising speed—it’s your go-to for those slow, deliberate crawls over challenging obstacles or treacherous terrain. Think of it as your secret weapon when you’re crawling over boulders, tackling steep hills, or ploughing through deep mud.

Ideal Scenarios for 4L:

• Extreme Off-Roading and Crawling Over Obstacles: One of the toughest tracks I’ve driven was near the Grampians in Victoria. The terrain was rocky, unpredictable, and littered with large boulders. When you’re driving over obstacles like this, 4L gives you the maximum torque needed to slowly crawl over without losing traction. It’s not about speed—it’s about control. With 4L engaged, the vehicle moves at a pace that feels slow and steady, allowing the tyres to grip and maintain traction, which is essential when navigating rough, uneven ground.
• Steep Grades (Up and Down): Whether you’re ascending a steep hill in the Flinders Ranges or descending a daunting slope, 4L is what you need. It provides engine braking, reducing the strain on your brakes, which is especially important when going down a hill. I recall driving down a particularly steep section of a track in the Snowy Mountains—the steep terrain would’ve caused my brakes to overheat quickly, but with 4L engaged, I didn’t have to touch the brake pedal once. The engine’s braking mechanism did all the hard work, allowing me to focus on steering.
• Deep Mud, Sand, or Snow: One memorable off-road trip in Western Australia had me stuck in deep mud. 4L was the only setting that helped. The extra torque and controlled speed were essential to getting out of the mud pit. If you’re driving in deep, soft sand or thick snow, 4L allows you to power through without spinning your wheels and digging yourself deeper into the mess.
• Heavy Towing: When towing a heavy load—whether it’s a boat or a large trailer—4L makes the task easier. It provides the high torque needed to move heavy objects across difficult terrain. I’ve used it to tow a heavy camper trailer up a hill in the Victorian High Country, and the 4L made a huge difference. It gave me that extra pulling power, making the towing process smoother and preventing the engine from bogging down.
• Vehicle Recovery: If you’ve ever found yourself stuck—whether in mud, sand, or snow—you know the frustration. I’ve had a few close calls, especially when the vehicle gets buried in soft sand at Stockton Beach. That’s when 4L comes in handy. It lets you crawl at a controlled pace, giving you the best chance of recovering the vehicle without making things worse. If you’re stuck in deep snow, the additional torque helps turn the wheels slowly and steadily, offering enough power to get free.

Key Notes for 4L Use:

• Speed is Your Enemy in 4L: When using 4L, slower is better. The maximum speed should be around 10 to 15 mph (16-24 km/h), and the absolute maximum is 25 mph (40 km/h). Anything faster than that puts unnecessary strain on the drivetrain. Imagine trying to rush through a rocky trail in 4L—your engine will be overworked, and you’ll put unnecessary stress on the transmission. Keep it slow, and let the vehicle do the heavy lifting.
• Engagement and Strain on the Engine: Shifting into 4L puts extra strain on the engine. It might feel a bit rougher compared to the smoother operation of 4H, but it’s built to withstand it. This is especially important to remember when driving up steep inclines or crawling over big rocks. The torque multiplication provided by 4L allows you to handle those rough spots, but it’s crucial to avoid riding the throttle too hard. Instead, focus on maintaining a steady pace.
• Shifting Into 4L: Shifting into 4L requires more care compared to 4H. It’s not something you should do while speeding along. If you’ve ever found yourself stuck and trying to shift into 4L, you’ll know it’s a different experience than shifting to 4H. When you’re at low speeds (about 2-3 mph), engage the Neutral gear, then carefully shift the transfer case lever to the 4L position. If there’s any resistance, take a breath, stop, and try again—it’s important to let the gears align properly to avoid damaging the system.

Shifting Procedures for 4L (Four-Low): Precision Matters

Engaging 4L (Four-Low) is not as straightforward as switching into 4H—it requires a bit more care and attention to ensure you don’t damage your vehicle’s drivetrain. When you engage 4L, you’re effectively slowing your vehicle down to a crawl while significantly increasing torque. This high power at low speed is what lets you crawl over obstacles and steep grades with precision. But, to make sure your transfer case and transmission are properly engaged, it’s essential to follow the correct procedure.

Steps for Shifting Into or Out of 4L (Low-Range)

1. Slow Down First: The first rule is don’t rush. 4L is not for high speeds. Before you attempt to engage 4L, slow your vehicle down to about 2-3 mph (3 to 5 km/h). It’s important to come to a complete stop if you can, especially if you’re on extremely rough terrain where shifting could cause strain. If you’re rolling a bit, the transfer case gears may not align properly, so try to find the right speed to engage smoothly.
2. Shift to Neutral: Once you’ve slowed down, move your vehicle’s main transmission into Neutral (N). If you’re driving a manual transmission, press the clutch pedal. If you’re in an automatic vehicle, make sure it’s in Neutral and the vehicle isn’t in motion. This step is crucial because it disengages the transmission and allows the transfer case to shift properly into 4L.
3. Engage 4L: With your vehicle in Neutral, the next step is to shift the transfer case lever to the 4L position. Take your time here—there’s no need to rush. You may feel a bit of resistance, but don’t force the lever. If there’s difficulty engaging, make sure you’re at the right speed and that the vehicle is fully stopped or moving at a crawl. In some cases, it’s necessary to rock the vehicle slightly to get the gears aligned properly.
4. Troubleshooting: If you’re struggling to engage 4L (which can happen if the gears don’t align perfectly), there are a couple of things to try. If you’re in an automatic, one trick is to turn off the engine momentarily. This can relieve pressure on the gears and allow for smoother engagement. For manual transmissions, depressing the clutch pedal while slightly moving forward or backward can help realign the gears.
5. Resume Driving: After successfully engaging 4L, shift your vehicle’s main transmission back into Drive (D) or the appropriate gear, and you’re ready to continue your crawl. With 4L, you’re in control, so take it slow and steady. Remember, speed is not your friend here—torque is, and the lower the speed, the more manageable the torque is.

Important Tips for Using 4L:

• Avoid High Speeds: It’s tempting, especially on long descents, but 4L is meant for slow, steady movement. Going faster than 25 mph (40 km/h) in 4L risks putting significant strain on the engine and transmission.
• Engine Strain: While 4L reduces strain on the drivetrain in steep inclines, it still places a heavy load on the engine because of the high torque. Keep an ear out for the engine’s response—if it feels like it’s overworking, ease off the throttle.
• Use When Needed: If you don’t need to crawl through obstacles or extreme terrain, 4H is the better choice. Using 4L unnecessarily can cause engine strain and waste fuel.

Common Misconceptions About Speed in 4WD: Separating Fact from Fiction

When it comes to using 4H and 4L in off-road vehicles, there are several common myths and misconceptions about speed that can lead to confusion or even damage to your vehicle if misunderstood. Whether you’re new to off-roading or a seasoned pro, it’s essential to get these details right to keep your vehicle in top condition.

Misconception 1: You Can Use 4L at High Speeds

One of the most persistent myths I’ve come across is the idea that 4L can be used at high speeds. Let me clear this up: 4L is not for speed. It’s designed for low-speed crawling, where torque is more important than speed. For example, in tough terrain like deep mud, rocky paths, or steep inclines, you need torque to push through, not speed.

The maximum recommended speed in 4L is 25 mph (40 km/h), and most off-road experts (including myself) suggest keeping it much slower—10 to 15 mph (16-24 km/h) is ideal for maintaining control and minimising strain on the drivetrain. I’ve made the mistake of pushing my vehicle too fast in 4L during a rock climb, and the result was unnecessary engine strain and poor performance. The lower the speed, the better your vehicle performs in 4L. Speed is your enemy here!

Misconception 2: 4H is for All Off-Road Conditions, Including Highways

Another myth I’ve heard too often is that 4H can be used on highways in any off-road conditions. While it’s true that 4H allows you to drive at higher speeds compared to 4L, it’s not designed for all off-road conditions, and definitely not for dry pavement. On highways, 4H works well on slippery surfaces like ice, snow, or loose gravel, but using it on dry pavement can cause drivetrain binding. This happens because the front and rear axles are locked together, forcing them to rotate at the same speed. On dry roads, the wheels need to rotate at different speeds (especially when turning), and this difference can cause excessive friction and strain on the drivetrain.

I’ve found that driving in 4H on dry pavement—even in light rain or wet conditions—can result in excessive tyre wear, difficulty steering, and ultimately damage to the drivetrain if done over long distances. To avoid this, always make sure the road or surface is slippery enough to allow the necessary wheel slip for 4H to function correctly. If you’re ever in doubt, shifting to 2H is the safest bet when driving on dry or hard-surfaced roads.

Misconception 3: 4L Works Fine on Highways for Steep Descents

I once met an off-roader who swore by using 4L for highway downhill descents. While it’s true that 4L provides excellent control on steep slopes during off-road driving, it is not meant for highway descents. 4L puts the engine under a lot of strain at higher speeds, and using it on highways can cause the engine to operate at high RPMs for long periods, leading to engine wear and fuel inefficiency.

In fact, 4L is best used in off-road situations where you need to crawl over obstacles or climb steep inclines at slow speeds. When driving downhill on a highway, it’s far more efficient and safe to rely on your vehicle’s brakes and engine braking in the normal gear range. Engine braking allows you to maintain control without over-revving the engine or straining the drivetrain.

Misconception 4: You Can Switch Between 4H and 4L on the Fly, Just Like 2WD

Another misconception that often pops up is the idea that you can switch between 4H and 4L while driving at any speed. While switching between 2H and 4H can be done while the vehicle is moving (up to speeds of about 55 mph), shifting into 4L requires more caution.

4L should only be engaged when your vehicle is moving slowly—no faster than 2-3 mph (3-5 km/h). The low-range gearing in 4L requires that the vehicle be almost at a complete stop to engage smoothly. Shifting into 4L while driving too fast can cause mechanical stress, misalignment of gears, and potential damage to the transfer case. Always reduce speed before attempting to engage 4L.

I’ve found that if you shift into 4L without stopping or reducing speed sufficiently, the transfer case might “grind,” and it could take several attempts to fully engage the gears. Not only is this frustrating, but it can also lead to unnecessary wear and tear on the vehicle’s drivetrain.

Best Conditions for 4H and 4L: Maximising Efficiency and Performance

To make the most of your 4WD system, it’s important to understand the specific conditions where 4H and 4L will serve you best. Using the wrong setting in the wrong conditions not only reduces your vehicle’s performance but can also cause damage.

Best Conditions for 4H (Four-High)

• Moderate Slippery Surfaces: 4H is best when you’re dealing with roads that are icy, snowy, or wet but still need to maintain speed. It’s ideal for those snowy mornings in Canberra, when the roads are slushy, and you need to make your way through the city without getting stuck.
• Gravel or Dirt Roads: When you’re cruising along unpaved surfaces in the Murray-Sunset National Park, where the terrain is a mix of firm dirt and light gravel, 4H provides just enough traction to keep your vehicle moving forward without sacrificing speed.
• Mild Off-Road Terrain: 4H is perfect for moderate inclines, declines, or shallow mud where you need to keep moving but with added traction to avoid slipping.

Best Conditions for 4L (Four-Low)

• Extreme Off-Roading: When you’re crawling over large rocks or mud in the Dandenong Ranges or Simpson Desert, 4L is your best option. It provides the maximum torque for slow, deliberate movement.
• Steep Grades and Slopes: Whether you’re tackling a steep hill or a downhill descent in the Flinders Ranges, 4L ensures that you can safely crawl up or down with maximum control.
• Deep Mud, Snow, or Sand: If you’re stuck in deep snow in the Snowy Mountains or sinking into soft sand on the Gold Coast, 4L ensures that your vehicle can power through with low-speed precision.

Both 4H and 4L are essential to your off-roading toolkit, but they are best used in specific conditions. 4H offers the right balance of traction and speed for moderate conditions, while 4L provides the maximum torque and control for the toughest, slow-moving situations. Remember, the key to using 4WD modes effectively is understanding the conditions at hand, knowing when to shift, and following the correct procedures to protect your vehicle’s drivetrain.