Do you not know why your 4 wheel drive jerks when turning? This article has all the answers.
When you are driving on a low traction surface such as muddy tracks, snow, or sand, it is pretty convenient to switch from two-wheel drive to four-wheel drive—the only thing to consider is that your speed should be below 62 mph.
Low traction surfaces are the ideal condition for 4WD if you don’t want to damage your drivetrain. The problem arises when you switch driving on a tarmac without changing the 4H (4WD, high range) setting and drive 4WD for some time.
Once you engage the 4H, the 4WD powers all four wheels, it is common to face difficulty while driving in the four-wheel-drive mode on high traction surfaces such as concrete and tarmac.
The primary problem you will face is turning corners because the outside wheels of the truck require to turn faster than the inside wheels. After all, it has to travel a greater circumference. Therefore, driving in the part-time four-wheel-drive mode on a high traction surface for long periods results in drivetrain windup or axle binding.
Let’s discuss these issues in detail and some of their solution.
4 Wheel Drive Locking Up While Turning (Drivetrain Binding)
Many people find their vehicles to understeer a lot, and the gears getting jammed, it occurs due to the windup effect. As a result, it makes your driving jerky.
The primary reason for this occurrence is the front wheels countering the rotational force of the forward driveshaft. The front driveshaft attempts to synchronize both the front wheels, which causes the heavy under-steer effect we just discussed.
Therefore to prevent this problem, you need to withdraw engaging four-wheel-drive on high traction surfaces for a long time. If you keep driving in the 4WD mode, you can probably severely damage the vehicle’s drivetrain components. Furthermore, it will be even more challenging to change it from 4H or 4WD to 2WD mode.
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How Can You Fix The Transmission Wind Up
As we already discussed, you’ll face transmission windup if you keep your 4WD on 4H while driving on Asphalt/Bitumen. A jammed/stuck-in gear is a great way to determine if your car has a transmission windup.
What happens is that you won’t be able to hang or yank on the gear lever since the gear will not release because the massive forces that build up inside the gearbox jam the transmission components. But how can you reverse the transmission windup?
The best way to fix the transmission windup is to pull over to the road’s side with two wheels on a smooth surface like sand, mud, or grass and two wheels firmly on the bitumen/asphalt. It lets the different wheels rotate at somewhat different speeds, releasing the windup in the car’s transmission.
After the windup releases, you can use the transmission/gearbox like they are supposed to be used.
Another option for this problem can be to reverse your car in the exact direction you were driving. For instance, if you are going forward in the left direction, reverse the car in the left direction, allowing the transmission’s windup to undo itself with time.
Note: Try to perform both the procedures in a safe environment without any pedestrians or oncoming traffic.
What Are Part Time 4 Wheel Drive Systems?
In four-wheel-drive systems, the differentials are fixed to the rear and front axle assemblies. The round bell housing, known as “pumpkin” underneath the vehicle, is the lowest part of your car.
If you’re driving the vehicle in 2H (2WD, high range), the power goes from the engine to the transmission by the rear propeller driveshaft to the rear differential. After that, it splits fifty-fifty between the rear wheels and rear axle shaft.
All the wheel axles are connected to a different side gear that meshes with the pinions. When the vehicle is going straight, all its wheels and side gears turn at an identical rotational speed.
Relative motion between pinions and differential side gears does not exist. They rotate together with ring gear and case. But the wheels of the vehicle twist at varying speeds when turning because of the gears inside the differential.
When you switch to four-wheel drive, the rear and front axles are connected by the transfer case transmitting fifty-fifty identical torque to the rear and front driveshafts. The drive is transferred by both the rear and front axle assemblies.
When the vehicle turns, the outer forward wheels swirl to create a broader turning circumference than the inner rear wheels. It creates variation in the rotational speeds in the rear and front wheels and, as a result, makes a difference in the rear and front driveshafts speed.
Therefore the speed difference between the outer and inner wheels makes both the axle shafts rotate at different speeds. You can also observe speed differences because of the uneven tire wear in the rear and front wheels or inflation pressure fluctuations.
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Should You Turn Your Vehicle In 4 Wheel Drive?
In permanent four-wheel drive mode, the car mechanism utilizes the center differential inside the transfer box, causing differences in rotation between the rear and front driveshafts, wheels, and side-shafts.
Because of the center differential, the rear and front driveshafts or propellers rotate at varying speeds while sending identical torque to both front and rear.
The driver has the control to lock the center differential when he engages the 4H in a part-time four-wheel drive or in a permanent four-wheel drive. Because of this procedure, the rear and front driveshafts are locked together, making them function and turn at an identical speed. The traction faced by the wheels does not matter in this situation.
It’s observed that when the driver engages the center differential lock in both permanent and part-time four-wheel-drive vehicles, the rear and front driveshafts are fixed inside the transfer box. The transmission can’t absorb the speed difference in driveshafts.
As a result, the torsional stress causes drive-line binding, axle binding, or drive-line windup. Therefore it is so challenging to turn your vehicle into the four-wheel-drive mode without causing the jerking effect.
Frequently Asked Questions
Why does my steering wheel jerk when turning?
When you are on 4WD mode and try to turn on a high traction surface like concrete, the difference in the speeds of the front wheels and rear wheels jams the gearbox, making your vehicle jerk. The steering wheel often jerks just because of the loose bearings in the steering rack, making it move without any input.
Is turning in 4 wheels drive bad?
Turning in 4 wheel drive is usually not an issue on smooth surfaces like grass or mud, but driving your vehicle on high traction surfaces for extended periods results in drivetrain windup or axle binding. It primarily happens because of the front and rear wheels operating at different speeds.
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What causes drivetrain binding?
The center differential of the transfer box causes differences in rotation between the rear and front driveshafts, wheels, and side shafts. Even though they operate at different speeds, they have the same torque, which locks both the front and rear driveshafts. Therefore the torsional stress causes the drivetrain binding.
This article covered all the necessary aspects of why four-wheel drive jerks while turning and a few tips on countering the issue. Make sure to share this article with anyone facing the same problem.