What Happens When Your Truck Is Stuck In 4-wheel drive? You had some offroad fun and are now ready to hit the road back but you can’t get your 4WD to disengage. Perhaps you drove in 4WD on the highway for extended periods. This is not a pleasant situation and there are a few fundamental things you need to consider before proceeding.
Drivetrain binding occurs when you drive in 4WD on a high-traction surface for extended periods resulting in your drivetrain becoming tightly wound. To solve this, park both wheels on one side onto a low traction surface such as sand, grass, or snow while driving slowly about 2 car lengths backward and forward. While doing this try to disengage the 4WD shift lever to release the tension in the transmission and allow you to select 2wd.
In a case like this, you want to try to loosen the tension as best as possible without causing serious damage to your transmission or transfer case.
With the advancement of technology in 4WD systems, each 4WD might have a different cause for getting jammed in 4WD mode. Depending on which vehicle you drive, the problem might even be electronic. Let’s now look at a few scenarios that best suit your 4WD type.
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Your Truck Is Stuck In 4-Wheel Drive? – Permanent 4WD’s
Permanent 4WD means the vehicle cannot be removed or taken out of 4×4 or 4H mode. This means the vehicle is always in 4H mode and functions very similar to an AWD vehicle. There is no risk of operating and driving it on ANY particular surface in this mode. Traditional Permanent 4WD trucks make use of a drive-train component (viscous coupling) that allows the drive shafts to operate independently while turning without causing any drive-line wind-up.
NB: if your 4WD has the ability to lock its center differential, always ensure that it is disengaged or unlocked before you venture back onto the tarmac or any hi-traction surface.
Part-time 4-wheel drive or 4×4 means the vehicle can be operated in 2-wheel drive mode as well as 4WD mode and this is up to the driver’s discretion. These modes can be selected with a short gear stick in the older 4×4’s or the more modern Utes and trucks make use of an electronic 4×4 turn dial option.
Most vehicles with part-time 4WD modes have a low-range transfer case making it very capable off-road, much more so than AWD vehicles. Part-time 4WD vehicles are propelled by the rear wheels in 2H mode, usually on the tarmac and other high traction surfaces. This allows the vehicle to deliver decent fuel economy on-road while having the ability to offer excellent off-road capabilities in 4H and 4Lo when needed.
Let’s look at a few common causes of 4WD systems getting jammed.
Most 4WD trucks have a component called an actuator which plays a key role in your 4WD system. The actuator is designed to automatically lock the wheel hubs when selecting 4H. When you engage your 4WD, the transfer case engages the front drive shaft to send torque to the front axle. The Actuator allows you to engage or disengage 4WD on your vehicle without the hassle of exiting the vehicle to manually engage the front hubs.
Faulty Transfer Case
As you might have gathered by now, there are many reasons why your 4WD fails to disengage 4H. It could be any of the following:
- bent or broken gear link
- low transfer case oil
- bad actuator
- drivetrain binding etc.
The transfer case gears could also be damaged thus resulting in your 4WD being jammed in 4H. This of course is the worst case scenario and requires the transfer case to be removed and stripped by a professional to assess the damage.
Damaged or Loose Gear Linkages
The factory linkages on certain older model Jeep Wranglers have been known to work themselves loose or break completely. The TJ Wranglers 4WD operating ranges are selected with a floor-mounted shift lever. The shift lever is connected to the transfer case range lever by an adjustable linkage rod.
The short low-range gear selector requires a nice firm yank to get it into and out of 4H properly. The newer, more modern Wranglers make use of a dial function that operates an electric motor to engage 4WD.
If the linkage has just worked itself loose, this can be caused by old age or regularly traveling on corrugated roads. It’s a relatively simple procedure to adjust the linkage and all you’ll need to do is, adjust the set screw, and you’ll be good to go.
Low Transfer Case Oil
You need to also make sure the transfer case fluid is topped up. When draining the TC, check for any metal filings. This will indicate excessive heat build-up caused by high levels of friction.
If the lubrication levels are low, the friction will increase causing major wear on gearing components. This will also result in the transfer case not engaging and disengaging properly when you are driving and attempting to switch to 4WD mode or switch back to 2H mode before driving on a high traction surface.
- Forgetting to switch from 4WD to 2WD on high-traction terrains may cause transmission wind-up.
- Transmission wind-up is indicated by the vehicle being stuck in gear and difficult to release manually.
- To fix the bind-up, park with two wheels on a high-traction surface and two wheels on a low-traction surface.
Drive forward a short distance and then reverse with the wheels still turned in the same direction. This will help release the tension in the transmission and alleviate the bind-up. It is important to remember that this technique should only be attempted in a safe and controlled environment. Additionally, regularly switching from 4WD to 2WD on high-traction terrains can help prevent transmission wind-up and avoid potential issues.
The solenoid calculates the difference in pressure of your vacuum pipes, which allows it to engage and disengage in 4WD mode. If you experience the 4WD symbol flashing on the dash without attempting to engage 4H then you need the check your solenoid. When this happens there are often grinding noises coming from your drivetrain as your 4WD systems try to engage while you are driving.
Unless traction is low, It is not advised to drive in 4WD mode for extended periods with a non-permanent 4WD as this will result in “axle binding”, also known as ”drive-line binding” or “drive-line wind up”. Extended driving in 4-Hi, with a part-time 4WD truck, on a high traction surface like pavement, will result in drive-train components like u-joints, axle, transfer gears, bearings, and drive-shafts getting damaged and eventually failing.