How to Use a Jeep's Four-Wheel Drive: 2H, 4H, 4L, and When to Use Each

A Wrangler or Gladiator with a part-time transfer case (Command-Trac or Rock-Trac) lives in 2H on pavement, goes into 4H for loose or slippery surfaces at normal speeds, and drops into 4L for crawling, steep grades, deep mud, deep snow, and anything that needs maximum pulling power at walking pace. The owner's manual allows the 2H to 4H shift while stopped or rolling, with 0 to 45 mph as the preferred window. 4L needs the transmission in NEUTRAL (or the clutch in) with the Jeep rolling at 1 to 3 mph, and it is capped at 25 mph. The rule that matters most: 4H and 4L lock the front and rear driveshafts together, so on dry pavement they bind the driveline. A Selec-Trac or full-time Rock-Trac case adds a 4H AUTO mode that is safe on any surface.

In this article

• What 2H, 4H, N, and 4L actually do
• Why part-time 4WD must stay off dry pavement
• Which transfer case your Jeep has
• The shifting procedure, straight from the manual
• Full-time systems: Selec-Trac, 4H AUTO, and Quadra-Trac
• Which mode for which terrain
• Where lockers and the sway bar disconnect fit in
• Common mistakes
• Frequently asked questions

What 2H, 4H, N, and 4L actually do

The second lever on the floor is the transfer case lever. The transfer case sits behind the transmission and decides whether the engine turns only the rear driveshaft or both, and whether it does so 1:1 or through a reduction gear set. The 2021 Wrangler owner's manual describes the four-position case used with Command-Trac and Rock-Trac like this:

Three details from the manual are worth remembering. A 4WD indicator in the cluster confirms the shift finished. In 4L, the engine turns roughly three times as fast as it would in 2H or 4H at the same road speed (four times on a Rubicon), so a Jeep that sounds frantic at 20 mph in low range is behaving normally. And transfer case N disconnects both driveshafts, so a Jeep left in N will roll even with the automatic in PARK or a manual in gear. Set the parking brake every time.

Why part-time 4WD must stay off dry pavement

A part-time transfer case has no center differential. In 4H or 4L, it mechanically locks the front and rear outputs, forcing the two driveshafts to turn at exactly the same speed. The manual says it plainly: 4H "maximizes torque to the front driveshaft, forcing the front and rear wheels to rotate at the same speed."

That is fine in a straight line. In a turn, it is a problem because the two axles do not travel the same distance. The front wheels steer, so they sweep a wider arc than the rear wheels, which cut inside the front wheels' path. Around a parking lot, the front axle covers more ground than the rear, so the front driveshaft wants more revolutions than the rear one. The transfer case will not allow that. Something has to give.

On gravel, snow, sand, or mud, the tire gives. One end of the Jeep slips a fraction of an inch per revolution, and nobody notices. On dry pavement, the tires grip too well to slip, so the mismatch winds up as torque in the driveshafts, the transfer case, the axle gears, and the front hubs. The symptoms are easy to spot: the steering fights you in a tight turn, the Jeep hops, a tire chirps as it breaks loose, and the lever gets hard to pull back into 2H because the wound-up torque is holding the shift collar. The manual says that 4H or 4L on hard-surfaced roads "will cause increased tire wear and damage to the driveline components."

This is also why the manual insists on four tires of equal size, type, and circumference. A tire slightly smaller than the other three turns faster at the same road speed, which builds the same mismatch on a straight road; any difference "will adversely affect shifting and cause damage to the transfer case." Mixed tread depths, an odd spare, and unequal pressures all count, so re-check pressures after a trail day using the airing down guide. Note that the lock is front to rear, not side to side: each axle's differential still lets its left and right wheels turn at different speeds. Lockers change that, and they're below.

Which transfer case your Jeep has

The trim level tells you which case is under the floor. The names below come from the 2021 Wrangler fact sheet and the 2021 Gladiator fact sheet on the Stellantis media site.

The low-range number is the point of the Rubicon case. Low range multiplies torque and slows the wheels for a given engine speed, and 4:1 does roughly half again as much of that as 2.72:1. Stellantis publishes the result as a crawl ratio (first gear, low range, and axle ratio multiplied together): at the 2018 Wrangler JL launch the figures were 84.2:1 for a manual Rubicon and 77.2:1 for an automatic, against 48.18:1 and 44.20:1 for Sport and Sahara. In practice, a Rubicon in 4L can idle down a ledge that a Sport has to ride the brakes on. The trim level guide sorts out which packages change the hardware.

The shifting procedure, straight from the manual

These are the owner's manual steps for the four-position case; the five-position Selec-Trac case uses the same speeds. The case has a shift collar and no synchronizer, so the method matters.

2H to 4H, or 4H back to 2H

1. Shift with the Jeep stopped or moving. The manual's preferred shifting speed is 0 to 45 mph (72 km/h).
2. Pull the lever into 4H with a steady, constant force. Do not accelerate while shifting.
3. If the Jeep is moving, momentarily lift off the accelerator after completing the shift; the manual says the case engages or disengages faster when you do.
4. Confirm the 4WD indicator in the cluster.

Two notes from the same section. Never shift while only the front or only the rear wheels are spinning; the driveshaft speeds must match for the collar to engage, and shifting during wheelspin can damage the case. And shifts out of 4WD can be delayed by uneven tire wear, low or uneven pressures, heavy loading, or cold temperatures; effort also rises with speed and until the fluid warms, which is normal.

4H to 4L, or 4L back to 4H

1. Slow to a roll of 1 to 3 mph (2 to 5 km/h).
2. Shift an automatic transmission into NEUTRAL, or press the clutch pedal on a manual.
3. While still coasting at 1 to 3 mph, move the lever firmly to 4L. Do not pause with the transfer case in N.
4. Once the shift is complete, put the automatic back into DRIVE or release the clutch.

The manual allows the 4L shift at a dead stop but warns that the mating teeth may not line up and it can take several tries; rolling at 1 to 3 mph is the preferred method, and it says not to try 4L any faster than that. Its blanket warning covers every shift: a position that is not fully engaged can damage the case or cause a loss of power and control, so do not drive until the lever is home and the cluster agrees.

Full-time systems: Selec-Trac, 4H AUTO, and Quadra-Trac

A full-time transfer case solves the binding problem with a clutch between the front and rear outputs, so the two driveshafts can turn at different speeds when they need to. On the Wrangler and Gladiator, that is Selec-Trac (2.72:1 low) on Sport, Sahara, and Overland, or the full-time Rock-Trac (4:1) on the Wrangler Rubicon. Both have five lever positions, and the manual describes the two 4H modes differently:

• 4H AUTO: the front axle is engaged, but power goes to the rear wheels until the Jeep senses a loss of traction, then four-wheel drive engages on its own. The manual lists 4H AUTO alongside 2H as a position for "normal street and highway conditions on dry hard-surfaced roads," noting that 2H returns better fuel economy because the front axle is disconnected.
• 4H PART TIME: the same locked-together behavior as 4H on a Command-Trac Jeep, with the same loose-surface-only rule.

So a Selec-Trac owner can leave the lever in 4H AUTO through a snowy winter, pavement and all, and still has a locked 4H and a 4L for the trail. The shifting speeds match the four-position case.

The Grand Cherokee goes further. Its Quadra-Trac I, Quadra-Trac II, and Quadra-Drive II systems all use what the 2022 Grand Cherokee press kit calls an active transfer case that moves torque toward the wheel with the most grip; Quadra-Trac II and Quadra-Drive II add a two-speed case with a 2.72:1 low range, and Quadra-Drive II adds a rear electronic limited-slip differential. Those systems have no part-time 2H; the driver selects a Selec-Terrain mode, and the transfer case manages the split.

Which mode for which terrain

The manual's Off-Road Driving Tips section gives surface-by-surface guidance, and the table folds that in with the surface rule above.

A useful way to think about it: 4H changes where the torque goes, and 4L changes how much of it there is and how slowly the wheels turn. If the problem is grip, 4H usually solves it. If the problem is control at walking pace, pulling power, or holding the Jeep back on a descent, that is 4L. The manual sums up low range as the choice for "deep snow, mud, steep inclines, or sand where additional low speed pulling power is needed," and warns that four-wheel drive makes it easy to exceed safe turning and stopping speeds. Traction to go is not traction to stop.

Where lockers and the sway bar disconnect fit in

Four-wheel drive gets power to both axles. It does not guarantee power to both wheels on an axle, because an open differential still feeds the wheel that spins most easily. That is what the Rubicon's Tru-Lok lockers are for, and the manual ties them to the transfer case: the front and rear axle lock only works in 4L at 10 mph or less, disengages above 30 mph, and re-locks under 10 mph. On Rubicons with the rear-only mode, the rear locker alone can be used in 4H, but only with Off Road+ active and stability control fully off. The lockers article covers when they help and when they hurt, including why a locked axle fights you in a turn for the same reason a locked transfer case does.

The electronic sway bar disconnect follows the same logic: the manual only allows it in 4H or 4L, and the system reconnects the bar on its own above 18 mph, returning to off-road mode below 14 mph. Both features assume you are already in four-wheel drive on a surface where you should be. If you are reaching for the locker button in 2H, the transfer case lever is the step you skipped. The off-road glossary defines the terms.

Common mistakes

• Leaving a part-time case in 4H after the snow stops. The road dries, the tires grip, and every on-ramp winds up the driveline. Shift to 2H as soon as the pavement is bare.
• Forcing 4L at a stop, or at 10 mph. Both are outside the procedure. Roll at 1 to 3 mph, transmission in NEUTRAL, and move the lever firmly without pausing in N.
• Parking with the transfer case in N. Both driveshafts are disconnected, so PARK holds nothing. N is for flat towing, and the manual also says never to dolly-tow a 4WD Jeep with two wheels on the ground.
• Driving 4L like 4H. The manual lists a 25 mph cap. Low range is for speeds where you can count the lug nuts.
• Treating 4WD as a reason to drive faster. Locked driveshafts help you accelerate on a slick surface. They do nothing for braking distance or cornering grip.

Frequently asked questions

Can you shift a Jeep Wrangler into 4H while driving?

Yes. The owner's manual allows the shift between 2H and 4H with the Jeep stopped or in motion, with 0 to 45 mph as the preferred range. Keep steady pressure on the lever, do not accelerate during the shift, and lift off the gas for a moment afterward. Do not shift while the wheels are spinning.

How fast can you drive in 4L?

The manual says not to exceed 25 mph (40 km/h) in 4WD Low. Engine speed in low range is roughly three times what it would be in 2H or 4H at the same road speed, and roughly four times on a Rubicon, so the engine will tell you long before the speedometer does.

Why is it hard to get my Jeep out of 4H?

Most often the driveline is wound up from driving in 4H on a surface with grip. Drive a few yards straight on a loose surface, or back up a short distance, to relieve the torque, then shift with steady pressure. The manual also lists uneven tire wear, uneven pressures, heavy loads, and cold temperatures as causes of delayed shifts.

Is it bad to use 4WD on dry pavement?

With a part-time case (Command-Trac or Rock-Trac), yes. The driveshafts are locked together, so in any turn the driveline binds, and the manual warns of tire wear and driveline damage. A Selec-Trac or full-time Rock-Trac Jeep can run 4H AUTO on pavement, but its 4H PART TIME and 4L positions follow the same loose-surface rule.

Related reading on this site: When not to use diff lockers, airing down tire pressure guide, Jeep Wrangler trim levels explained, off-road terms glossary.