When I started off-roading few vehicles had any form of traction control, and the technique of approaching an obstacle was somewhat different. One had to read the obstacle carefully and use a little more momentum. Then came the limited-slip rear differential, an intervention that allowed a certain amount of power to be transferred to a wheel that had traction when the opposing wheel had lost traction.
This was followed by the locking rear differential, this feature allowed the wheel with traction to get 50% of the power available to the rear axle. Certain vehicles do have front lockers but that is not the norm.
Electronic traction control aids have been a game-changer, to 4×4’s as well as crossover vehicles. The only problem is the vehicle owner often walks away confused as to how they work. The systems are highly “intelligent” and in the main provide automatic assistance. Rear differential lockers are now standard on most 4×4’s with high and low range gearing. There are other systems in vehicles designed to reduce the loss of traction and to help regain traction. Electronic traction control systems use a series of wheel sensors to detect slip. When this takes place they direct power to the wheels that have traction. The technique here is to allow the system to do its job. If you apply too much power it can confuse the system. With Electronic Traction Control(ETC) there is often a slight noise as the ABS brakes a wheel to allow power to be transferred to an opposing wheel but you will soon get used to it if you are a newbie to ETC. Old school drivers often refer to these types of systems as nannies yet I recently drove a vehicle with ETC and a rear differential lock and even in the worst twisters where opposing from and rear wheels lost traction I did not even need to use the rear locker.
In the past top-end vehicles ( Large style SUV’s) were fitted with a vast array of aids yet nowadays it is not uncommon to find them on high and mid-spec bakkies.
Terrain selection is still a feature of the high spec SUV’s, this feature allows you to select a traction setting suitable for the terrain. Think snow and ice, mud, sand or rocky terrain. All these systems monitor wheel spin and through the ECU ( computer control unit ) deliver optimum power and braking for the conditions.
Snow settings generally balance power between the from and rear wheels to send more power to the front. It’s generally a 60/40% power distribution. Whilst on rocks more brake pressure would be delivered to stop wheel spin. However, on sand optimum power may be delivered to the rear wheel to maintain momentum. So one has to earn not to take your foot off the accelerator to regain traction. Rather hold on to steady power delivery. It will take a few seconds to kick in.
Then we get the beauty known as downhill assist, it controls your descent and negates a tendency to slide by braking wheels on the inside of a slide to keep the vehicle on track. It is intended for slow speeds so typically only engages in 4WD low range.
One also gets hill start assist, this feature senses that you are on an incline and brakes the vehicle for a few seconds. This ensures a smooth pull away as the clutch or torque converter engages after the handbrake is released. Yet even with all these aids, I am still a big fan of a locking rear differential. It has helped me so often in the past. If you buy a new vehicle and the manufacturer offers you training embrace it. Even if you have attended courses in the past this opportunity helps you catch up with the future.