When to Use 4H, 4L, Lockers in Jeep & RAM Vehicles

It’s no secret that Jeep is one of, if not the most world renowned automaker of off-road vehicles in the industry. The brand’s pedigree for building off-road icons is historic, and they’ve shown no signs of slowing that reputation down. RAM has begun building plenty of rugged, off-road vehicles of its own as well, with the RAM 1500 RHO as a prime example. But if you’re new to off-roading or four-wheel drive vehicles in general, it’s important that you learn and understand how to properly use these systems. For example, when you should use 4-High, 4-Low and axle lockers. That’s what we’re here to do today, to make sure customers here at Jim Glover CDJRF know exactly when and how to use these different systems within their Jeep and RAM vehicles.

The 4-High (4H) setting on your four-wheel drive system is designed to be used in situations that require more traction than normal but in which you’d like to maintain higher speeds. When triggered, 4H will engage both the front and rear wheels and distribute power evenly between all four, which leads to improved stability and grip on the surface. One thing to keep in mind is that you should really never trigger 4H while driving on dry pavement, as this can cause strain throughout your drivetrain and ultimately damage its components. Here are a few examples of times when you should consider switching to 4H:

• Snowy or icy conditions. Slippery surfaces are the best time to use 4H, as it provides the necessary traction to prevent skidding and maintain control.
• Dirt or gravel roads. Loose surfaces are very similar to slippery ones, plus 4H can greatly reduce the risk of getting stuck in debris.
• Minor off-road driving. While it isn’t designed for intense off-road scenarios, mild trail conditions and generic uneven terrain are perfect for 4H.

The 4-Low (4L) setting, on the other hand, is designed for your extreme off-road situations. It delivers maximum power and control while operating at low speeds, which is exactly what you want through a lot of off-roading excursions. Triggering the mode will make your Jeep or RAM vehicle switch to a lower gear ratio so that it can deliver increased torque. Much like 4H, it would be unwise to engage 4L on dry, flat surfaces. You also want to make sure you keep your speed as low as you can while it’s on, typically below 10 miles per hour, as going faster can also lead to damage throughout your drivetrain. But these are some good scenarios in which to use it:

• Rock crawling. With 4L engaged, you gain the prevision and power necessary for climbing over obstacles in your path.
• Deep mud or sand. Muddy, sandy surfaces can cause your wheels to spin and impede progress along your path, but not with 4L engaged.
• Steep inclines or declines. Whether ascending or descending, hills will be much easier with 4L thanks to providing the control required for steep grades.

A lot of vehicles throughout both brands’ lineups offer axle lockers as a standard of available feature. They were designed to enhance traction by locking the wheels on an axle together, ensuring that each wheel receives the same exact amount of power. This forces both wheels to rotate at the same rate, regardless of whether or not one has lost traction for some reason or another. You really only want to engage your axle lockers under certain circumstances, when driving at low speeds, as they can affect steering and handling negatively at higher speeds. For example, turning becomes quite difficult while your axles are locked. But here are a few examples of good times to engage them:

• Uneven terrain. Axle lockers are great for a lot of off-roading conditions, as they can ensure your wheels spin and provide the grip necessary to maneuver over uneven terrains. Rock crawling in particular is a great time to engage your axle lockers, as they’ll ensure you get the grip needed to climb over those bigger rocks.
• Mud, snow and similar sticky situations. Any time that a wheel can get stuck in something, such as mud or snow, engaging axle lockers can help ensure that the other wheel continues to receive power so you can move forward.
• Extreme off-road conditions. Naturally, the more challenging the trail and unpredictable the terrain, the more useful axle lockers are going to be in providing the stability and traction necessary to navigate safely. Just make sure you don’t go too fast!

If you have any questions about your four-wheel drive system or when to use any of the aforementioned features, don’t hesitate to give us a call right here at Jim Glover CDJRF. We look forward to hearing from you!