Nissan AD: four-wheel drive - device, modes and operating features

Owners Nissan AD (or Nissan Terrano II, as it is known in Europe) this SUV is valued for its reliability, simplicity of design and, of course, four-wheel drive. But not everyone understands exactly how the system works. 4WD in this model, what modes it has and how to use them correctly. Unlike modern crossovers with electronic "assistants", everything here is built on proven mechanical solutions - and therefore requires a conscious approach.

In this article we will look at all-wheel drive device for Nissan AD, we'll explain how to switch modes depending on road conditions, and warn about common mistakes that can lead to damage. You will also find out what The transmission of this model has unique features compared to other SUVs of the early 2000s.

All-wheel drive device on Nissan AD: diagram and principle of operation

All-wheel drive system Nissan AD (in the back R20) belongs to the type part-time 4WD - that is, connected manually. This means that under normal conditions the car drives only in rear-wheel drive, with the front axle engaging when necessary. This scheme is simpler and more reliable than permanent all-wheel drive, but requires the driver to understand when and how to activate 4WD.

Main components of the system:

• 🔧 Transfer case with two stages (reduction and direct transmission). Models with 2.7 TD And 3.0 TD equipped with a transfer case RL20A or RL20B.
• 🔄 Center differential — absent in the basic configuration (rigid connection of axes), in versions with Super Select may be blockable.
• 🚗 Cardan shafts front and rear axles with constant velocity joints (CV joint).
• 🔗 Front axle coupling — activated by a lever in the cabin.

When all-wheel drive is engaged, the torque is distributed between the axles in proportion 50:50. Important: on dry asphalt or at high speeds use 4WD it is impossible - this will lead to increased wear of the transmission and “knitting” of the drive. More details about this can be found in the section on modes.

All-wheel drive modes: when and how to use

B Nissan AD There are three main transmission modes available, switched by two levers: one is responsible for connecting the front axle, the second is for downshifting. Let's look at each option.

Switching between modes 2H ↔ 4H can be done on the go (up to 80 km/h), but it is better to do it in neutral gear. To activate 4L necessarily stop completely and depress the clutch. Trying to downshift while driving may result in breakdown of transfer case gears.

⚠️ Attention: If after switching to 4H or 4L If you hear a crunching or grinding noise, stop immediately and check the oil level in the transfer case. This may be a sign of worn synchronizers.

Differences between all-wheel drive systems in different versions of Nissan AD

Not all Nissan AD are the same: depending on the market and year of manufacture, they could be equipped with different types of all-wheel drive. For example, European versions Terrano II with engine 2.7 TD often had a system Super Select, which made it possible to connect all-wheel drive automatically (by type AWD). While basic models for the Middle East or Africa are equipped with classic part-time 4WD.

Key differences:

• 🔹 Super Select (SS4) - there is a mode 4H Auto, where the front axle is connected as needed (analogue All Mode 4WD at Mitsubishi).
• 🔹 Standard part-time - manual connection only 4H/4L, without automatic functions.
• 🔹 Differential lock - option for versions with Super Select, allows you to rigidly link the axles to overcome difficult areas.

To find out which system is installed on your car, check:

1. The presence of a differential lock lever (usually located next to the transfer lever).
2. Inscription Super Select on the instrument panel or in the documentation.
3. Mode 4H Auto on the selector (if available).

Typical all-wheel drive malfunctions and their symptoms

Even reliable mechanics Nissan AD wears out over time. Let's look at the most common problems with all-wheel drive and their symptoms.

1. Wear of the front axle coupling

Signs:

• 🔊 Crunch when turned on 4H.
• 🚗 Vibration at speeds above 60 km/h in 4H.
• 🔧 Spontaneous shutdown of the front axle.

Solution: replace the clutch or the entire front gearbox (depending on the degree of wear).

2. Oil leak from transfer case

Signs:

• 💧 Oil stains under the car in the transfer case area.
• 🔊 Howling sound when moving in 4H/4L.
• 🛑 Difficulty switching modes.

Solution: replace oil seals and gaskets, add oil (recommended GL-5 80W-90).

3. Wear of driveshafts or CV joints

Signs:

• 🔊 Clicks when turning in mode 4H.
• 🚗 Vibration at speeds of 80+ km/h.
• 🔧 Play in the hinges (checked by hand with the wheel hanging).

Solution: replacement of crosspieces, suspension bearings or cardan assemblies.

⚠️ Attention: If, after crossing a ford or a deep puddle, the four-wheel drive stops turning on, immediately check for water in the transfer case. Even a small amount of moisture can lead to gear corrosion and synchronizer failure.

All-wheel drive maintenance: what and when to check

So that the system 4WD on Nissan AD served for a long time, follow these recommendations:

1. Changing the oil in the transfer case

Interval: every 60,000 km or once every 3 years. Use oil API GL-5 with viscosity 80W-90 (For example, Mobilube HD or Castrol Syntrax Universal). Volume - approx. 1.5 l.

2. Checking cardan shafts

Every 20,000 km inspect:

• 🔧 Condition of the crosspieces (is there any play).
• 🔧 Suspension bearings (there should be no extraneous sounds).
• 🔧 Condition of CV joint boots (cracks or tears are unacceptable).

3. Diagnostics of the front axle coupling

Signs of wear appear after 100,000–150,000 km. For prevention, once a year lubricate the mechanism through grease fittings (use Litol-24 or analogues).

4. Checking the seals

Leaks usually appear after 80,000 km. Pay attention to:

• 💧 Front gearbox seal.
• 💧 Transfer case shank seal.
• 💧 Cardan flange seals.

How to properly operate four-wheel drive off-road

Nissan AD — a real SUV, but even it requires a competent approach to overcoming obstacles. Here are the key rules:

1. Mode selection

• 🏔️ Mud, snow, sand: use 4H. Downshift (4L) turn on only when you need to “swing” or on steep climbs.
• 🌊 Brody: turn it on before entering the water 4L and differential lock (if equipped). After overcoming, be sure to dry the brakes by lightly pressing the pedal.
• 🪨 Rocky road: avoid the regime 4H at high speed - this increases the load on the transmission.

2. Technique for overcoming obstacles

• 🔄 If you get stuck on diagonal hanging, try swing: alternate R ↔ D with the clutch pedal pressed.
• 🚗 On steep climbs, use 4L And don't drop the clutch suddenly - this can lead to damage to the transfer case.
• 🔧 If the wheel is slipping, place it under it ladders (boards, mats) or reduce tire pressure to 1.2–1.5 atm.

3. What to do if you get stuck

If the car cannot move:

1. Turn on 4L and differential lock (if equipped).
2. Try retracing your steps.
3. Use a winch or the help of another vehicle (but do not pull the cables too hard!).

⚠️ Attention: Long-term operation 4L at high speeds (for example, when trying to pull out of the mud) can lead to overheating of the transfer case. Optimal algorithm: short jerks with pauses to cool the transmission.

Upgrading all-wheel drive: what can be improved

Standard system 4WD on Nissan AD reliable, but some owners prefer to modify it. Let's look at popular upgrades:

1. Installing rear differential lock

Cost: from 30 000 ₽ (for example, blocking ARB Air Locker). Pros:

• 🔧 Significantly improves cross-country ability on diagonal hanging.
• 🚗 Allows you to overcome difficult areas without the risk of damaging the axle shafts.

Cons: requires installation of a compressor and regular maintenance.

2. Replacing the transfer case with a version with Super Select

If your AD equipped with a basic transfer case, can be installed Super Select from a donor. This will give:

• 🔄 Mode 4H Auto for automatic connection of all-wheel drive.
• 🔧 Center differential lock.

Cost: from 50 000 ₽ for a used transfer case + work.

3. Reinforced driveshafts

Standard cardans Nissan AD stand up to 250–300 hp, but when tuning the engine or installing large wheels (more 33") it is recommended to install reinforced shafts (for example, from Nissan Patrol GR).

4. Transfer case protection

The weak spot is the lower part of the transfer case. Install steel protection (for example, from Ironman 4x4) to avoid damage when hitting rocks.

FAQ: Frequently asked questions about Nissan AD all-wheel drive

- Состояние тяги управления раздаткой (не погнута ли она).
- Целостность пружины фиксатора рычага.