The Jeep Grand Cherokee (WJ) introduced a notable four-wheel-drive system option, offering drivers varying levels of control depending on terrain and driving conditions. This system provided a range of modes, from two-wheel drive for everyday paved roads to full four-wheel drive with low range gearing for challenging off-road situations. A defining feature was the ability to shift between these modes on-the-fly, enhancing both versatility and driver convenience.
This adaptable four-wheel-drive capability elevated the WJ’s performance and appeal, particularly for drivers requiring both on-road comfort and off-road prowess. It provided increased traction and control in adverse weather conditions like snow or ice and enabled drivers to navigate difficult terrain such as mud, rocks, and sand. This feature, coupled with the WJ’s overall design, solidified its position in the SUV market, appealing to a broad range of consumers seeking both functionality and adventure. The ability to shift between two- and four-wheel drive also contributed to fuel efficiency when four-wheel drive wasn’t necessary.
Understanding this system’s operation is crucial for maximizing the vehicle’s capabilities and ensuring optimal performance and safety. The following sections will explore its various modes, their respective applications, and recommended maintenance practices.
1. 2WD
The “2WD” or two-wheel drive mode within the Selec-Trac transfer case system of the Jeep Grand Cherokee (WJ) represents its default setting for on-road driving. In this configuration, power is directed solely to the rear wheels, optimizing fuel efficiency and providing a smoother ride on paved surfaces. This mode is best suited for everyday commuting, highway driving, and generally any situation where the enhanced traction of four-wheel drive isn’t required. Selecting 2WD reduces wear and tear on the drivetrain components associated with four-wheel drive operation, contributing to their longevity. For example, driving in 2WD on dry pavement reduces friction and heat buildup in the transfer case and front axle components.
The availability of 2WD within the Selec-Trac system highlights the WJ’s versatility. While equipped with a robust four-wheel-drive system for off-road capability, the WJ can function efficiently as a rear-wheel-drive vehicle for typical on-road use. This adaptability allows drivers to choose the most appropriate drivetrain configuration based on the prevailing conditions, balancing performance needs with fuel economy and mechanical wear. Switching to 2WD after off-road excursions, for example, immediately restores the vehicle’s on-road driving characteristics and fuel efficiency. Failing to utilize 2WD when appropriate can lead to decreased fuel economy and unnecessary stress on the four-wheel-drive system components.
Understanding the function and application of the 2WD mode within the Selec-Trac system is essential for maximizing the WJ’s overall efficiency and operational lifespan. Choosing the correct drivetrain setting for the given conditions is crucial for both performance and maintenance considerations, contributing significantly to the long-term reliability and versatility of the vehicle. The proper utilization of 2WD ensures optimal performance and efficiency in everyday driving scenarios and contributes to minimizing long-term maintenance requirements.
2. 4WD Part-Time
The “4WD Part-Time” mode in the Jeep Grand Cherokee (WJ)’s Selec-Trac system represents a crucial step up from two-wheel drive, engaging all four wheels for increased traction when needed. Unlike the “Full-Time” option, this mode is specifically designed for situations where the added grip of four-wheel drive is beneficial but not constantly required. This makes “Part-Time” ideal for specific off-road conditions or challenging on-road scenarios like snow or ice.
-
Enhanced Traction
Engaging 4WD Part-Time delivers power to both front and rear axles, significantly improving traction compared to 2WD. This is particularly advantageous on loose surfaces like gravel, dirt, or sand where two-wheel drive can struggle to maintain grip. For instance, navigating a muddy trail or climbing a steep, unpaved incline becomes considerably more manageable with all four wheels working in tandem to propel the vehicle. This enhanced traction, however, should not be employed on dry, paved surfaces as it can create binding in the drivetrain.
-
Manual Engagement
The “Part-Time” designation emphasizes the driver’s active role in activating this mode. Unlike systems that automatically engage four-wheel drive, Selec-Trac requires the driver to manually shift the transfer case lever into 4WD Part-Time. This conscious decision emphasizes the importance of using this mode only when necessary, promoting both mechanical efficiency and responsible driving. This manual engagement allows for precise control over when the additional traction is employed.
-
Temporary Use Case
4WD Part-Time is not intended for continuous use, especially on high-traction surfaces. Prolonged engagement on dry pavement can lead to drivetrain binding and increased tire wear. Consider its application: while beneficial during a snowstorm or on a muddy trail, it’s unnecessary and potentially detrimental during regular highway driving. Switching back to 2WD once the need for extra traction has subsided preserves drivetrain components and optimizes fuel economy.
-
Interaction with Other Systems
Within the WJ’s Selec-Trac transfer case, 4WD Part-Time operates distinctly from other available modes like 4WD Full-Time and 4WD Low. Understanding these distinctions is crucial for maximizing the vehicle’s capabilities while minimizing potential mechanical strain. For example, while 4WD Part-Time provides enhanced traction for moderate off-roading, 4WD Low is necessary for more extreme situations requiring maximum torque and control. The choice between these modes depends on the specific terrain and driving demands.
Effectively leveraging 4WD Part-Time enhances the WJ’s all-terrain capabilities, ensuring optimal performance when navigating challenging conditions. Recognizing its specific applicationsituations demanding increased traction without the need for constant engagementhighlights its strategic role within the Selec-Trac system and its contribution to the WJ’s overall versatility and off-road prowess. Misuse can lead to mechanical issues and reduced component lifespan, reinforcing the importance of informed operation.
3. 4WD Full-Time
The “4WD Full-Time” mode in the Jeep Grand Cherokee (WJ)’s Selec-Trac system represents a significant departure from both 2WD and 4WD Part-Time, offering continuous power delivery to all four wheels. This constant engagement alters the vehicle’s handling characteristics and provides enhanced stability and traction, particularly in adverse weather conditions or on surfaces with consistently low grip. Unlike 4WD Part-Time, which requires manual activation and is unsuitable for high-traction surfaces, 4WD Full-Time allows the vehicle to seamlessly transition between varying levels of grip without driver intervention. This capability is made possible by the presence of a viscous coupling unit within the transfer case, allowing for some slippage between the front and rear axles. This nuanced operation mitigates the drivetrain binding that could occur with a permanently locked 4WD system on high-traction surfaces. For instance, driving on a mix of snow-covered and clear roads becomes safer and more manageable with 4WD Full-Time, eliminating the need to constantly switch between 2WD and 4WD Part-Time. This continuous power distribution to all four wheels provides a predictable driving experience, increasing driver confidence and control in challenging conditions.
The inclusion of 4WD Full-Time within the Selec-Trac system expands the WJ’s adaptability, effectively bridging the gap between the efficiency of 2WD and the enhanced traction of 4WD Part-Time. This mode offers a balance between these two extremes, allowing drivers to maintain improved stability and control without the limitations or potential drawbacks of the other modes in specific scenarios. Consider driving on a rain-slicked highway: 4WD Full-Time provides enhanced grip without the need for constant manual shifting, unlike 4WD Part-Time, and avoids the potential instability of 2WD in such conditions. This capability adds another layer of safety and performance to the WJ, making it suitable for a wider range of driving environments. This adaptability translates directly into enhanced driver confidence and vehicle control, especially in unpredictable weather conditions or on varying road surfaces.
Understanding the functionality and appropriate application of 4WD Full-Time is crucial for maximizing the benefits of the Selec-Trac system. Its ability to provide continuous all-wheel drive without the limitations of a fully locked system highlights its unique role within the WJ’s drivetrain options. While not intended for serious off-roading where 4WD Low is required, 4WD Full-Time provides a valuable level of enhanced safety and control in everyday driving scenarios, particularly those involving unpredictable weather or varying road surfaces. This understanding allows drivers to fully leverage the WJ’s capabilities while preserving the integrity of its drivetrain components and optimizing performance for different driving conditions.
4. 4WD Low (N)
The “4WD Low (N)” mode within the Selec-Trac transfer case of the Jeep Grand Cherokee (WJ) represents the most specialized and powerful drivetrain option, reserved for extreme off-road situations. This mode significantly alters the gear ratios, providing maximum torque and control at very low speeds. Unlike other modes designed for on-road use or moderate off-roading, 4WD Low (N) focuses on maximizing the vehicle’s ability to navigate challenging terrain, including steep inclines, deep mud, rock crawling, and other situations requiring exceptional low-speed power and control.
-
Low-Range Gearing
The defining characteristic of 4WD Low (N) is its extremely low gear ratio. This reduction in gearing multiplies the engine’s torque output, providing significantly more power to the wheels at lower speeds. This is analogous to using a lower gear on a bicycle to climb a steep hill; it requires more pedaling effort but makes the climb manageable. In the WJ, this increased torque allows the vehicle to overcome obstacles and maintain traction in conditions where higher gearing would result in wheel slippage and loss of control.
-
Neutral (N) Position
The “(N)” designation within 4WD Low refers to the neutral position within the transfer case. This position disengages the drivetrain from the engine, allowing the vehicle to be towed without causing damage to the transfer case. While not directly related to the low-range gearing function, its inclusion within this mode underscores the context of 4WD Low as a specialized setting for specific off-road scenarios where towing might be required.
-
Controlled Descent
The low gearing of 4WD Low (N) is particularly beneficial for controlled descents on steep inclines. The increased engine braking effect at low speeds allows the driver to maintain precise control without relying solely on the vehicle’s brakes. This minimizes the risk of brake fade and loss of control, especially on loose or uneven surfaces. This controlled descent capability significantly enhances safety during challenging off-road maneuvers.
-
Specific Application
4WD Low (N) is not intended for everyday driving or even moderate off-road use. Its extreme low gearing makes it unsuitable for higher speeds and prolonged use on paved surfaces. Engaging this mode should be reserved solely for situations requiring maximum low-speed torque and control, such as rock crawling or navigating deep mud or sand. Utilizing 4WD Low (N) inappropriately can result in mechanical strain and reduced component lifespan.
The presence of 4WD Low (N) within the Selec-Trac system completes the WJ’s spectrum of drivetrain options, providing a dedicated mode for extreme off-road conditions. Its specific focus on maximizing low-speed torque and control makes it a crucial component of the WJ’s overall versatility and off-road capability. Understanding its intended use and limitations is paramount for both maximizing its benefits and preserving the integrity of the drivetrain system. This specialized mode significantly extends the WJ’s capabilities beyond typical SUV limitations, allowing it to tackle challenging terrain with confidence and control.
5. Transfer Case
The transfer case stands as the central component of the Selec-Trac four-wheel-drive system in the Jeep Grand Cherokee (WJ). This robust metal housing contains a set of gears that distribute power from the transmission to both the front and rear axles, enabling the various drive modes characteristic of Selec-Trac. Its operation is fundamental to transitioning between two-wheel drive (2WD) for fuel efficiency on paved roads, and four-wheel drive (4WD) for enhanced traction in off-road conditions or inclement weather. The transfer case’s ability to shift power distribution dynamically lies at the heart of the WJ’s adaptability, distinguishing it from vehicles with less sophisticated drivetrain systems. Consider a scenario where the WJ encounters a snow-covered road; the transfer case allows the driver to engage 4WD, distributing power to all four wheels for increased traction and stability. Without a functioning transfer case, this seamless transition would be impossible, limiting the vehicle’s capability and potentially compromising safety.
The transfer case’s internal gearing mechanisms directly influence the WJ’s performance across various driving conditions. Within the Selec-Trac system, the transfer case provides a range of drive modes, including 4WD Part-Time, 4WD Full-Time, and 4WD Low. These modes offer varying levels of torque and power distribution tailored to specific terrain challenges. For example, 4WD Low engages a lower gear ratio within the transfer case, multiplying torque output for tackling steep inclines or navigating deep mud. The transfer case’s ability to facilitate these different modes underscores its critical role in enabling the WJ’s off-road prowess. A failure within the transfer case can severely compromise the vehicle’s ability to navigate challenging terrain, highlighting the importance of proper maintenance and understanding its function.
A thorough understanding of the transfer case’s operation is essential for effectively utilizing the Selec-Trac system and maximizing the WJ’s capabilities. Recognizing the transfer case’s role in distributing power and facilitating different drive modes provides drivers with the knowledge to make informed decisions about drivetrain selection and maintenance. Ignoring the operational parameters of the transfer case can lead to premature wear, mechanical failure, and reduced off-road performance. Regular maintenance, including fluid changes and inspections, ensures the transfer case continues to function optimally, preserving the WJ’s adaptability and off-road prowess over its lifespan. Proper operation and maintenance safeguard the transfer case’s functionality, ensuring the WJ retains its versatile performance capabilities across diverse driving environments.
6. Shift-on-the-Fly
Shift-on-the-fly functionality represents a critical element of the Selec-Trac four-wheel-drive system in the Jeep Grand Cherokee (WJ). This capability allows drivers to transition between two-wheel drive (2WD) and four-wheel drive high (4WD High) while the vehicle is in motion, at speeds up to 50 mph (80 km/h). This feature significantly enhances the WJ’s adaptability to changing road conditions, offering convenience and improved safety. Consider encountering unexpected patches of ice or snow on a paved road; shift-on-the-fly enables a seamless transition to 4WD High without requiring the vehicle to stop, maintaining momentum and enhancing control. This dynamic shifting capability contrasts with older four-wheel-drive systems that mandated stopping the vehicle and manually engaging locking hubs.
The integration of shift-on-the-fly within Selec-Trac simplifies the process of adapting to varying terrain and weather conditions. This ease of use encourages drivers to utilize the appropriate drivetrain mode for the given situation, promoting both safety and fuel efficiency. For example, transitioning from 2WD to 4WD High when approaching a muddy off-road trail becomes a quick and straightforward operation, maximizing traction without interrupting the driving experience. Conversely, returning to 2WD after navigating the off-road section is equally seamless, optimizing fuel economy on paved roads. This flexibility highlights the practical benefits of shift-on-the-fly in real-world driving scenarios.
Shift-on-the-fly represents a key advancement in four-wheel-drive technology, contributing significantly to the WJ’s versatility and user-friendliness. This feature empowers drivers to respond effectively to changing road conditions, enhancing safety and control while simplifying the overall driving experience. Understanding the operational parameters and benefits of shift-on-the-fly is crucial for maximizing the capabilities of the Selec-Trac system. This knowledge allows drivers to utilize the appropriate drivetrain mode for any given situation, contributing to both improved vehicle performance and enhanced safety margins.
7. Quadra-Trac II
Quadra-Trac II represents the specific implementation of the Selec-Trac four-wheel-drive system within the Jeep Grand Cherokee (WJ). It’s a full-time four-wheel-drive system offering a two-speed transfer case with shift-on-the-fly capability between 2WD and 4WD High. This system utilizes a gerotor coupling, also known as a progressive coupler, in the transfer case. This component automatically directs torque to the axle with the most traction, enhancing stability and control. When one axle begins to slip, the gerotor coupling progressively transfers torque to the axle with better grip. This automatic torque biasing allows for seamless adaptation to changing road conditions, minimizing wheel slippage and maximizing traction without driver intervention. For instance, if the rear wheels lose traction on a patch of ice, Quadra-Trac II will automatically redirect torque to the front wheels, helping to maintain control and forward momentum.
Quadra-Trac II offers a combination of full-time 4WD capability with the fuel efficiency and drivability of 2WD on demand. This balance makes it suitable for a wide range of driving conditions, from everyday commuting to moderate off-road excursions. Its ability to automatically adjust torque distribution simplifies the driving experience, particularly in challenging weather conditions. For example, navigating a snow-covered road requires no manual shifting between 2WD and 4WD; Quadra-Trac II manages the power distribution automatically, ensuring optimal traction at all times. However, while capable in many situations, Quadra-Trac II, unlike more advanced systems like Quadra-Drive, lacks locking differentials. This means that in extreme off-road scenarios with significant wheel slippage, individual wheels can still lose traction, limiting overall capability.
Understanding Quadra-Trac II as the specific implementation of Selec-Trac in the WJ is crucial for appreciating the vehicle’s capabilities and limitations. The system’s combination of on-demand 2WD and automatic full-time 4WD provides a versatile and user-friendly driving experience, especially in variable conditions. Recognizing its automatic torque biasing capabilities and the absence of locking differentials informs appropriate usage and expectations. This knowledge ensures drivers can effectively utilize the system’s strengths while remaining aware of its limitations in extreme off-road scenarios. This understanding, combined with appropriate maintenance, allows owners to maximize the benefits of Quadra-Trac II and enjoy the WJ’s versatile performance.
Frequently Asked Questions
This section addresses common inquiries regarding the Selec-Trac four-wheel-drive system found in the Jeep Grand Cherokee (WJ). Clarity on these points contributes to informed operation and maintenance practices.
Question 1: What are the primary driving modes offered by the Selec-Trac system in the WJ?
The Selec-Trac system in the WJ offers four primary modes: 2WD for standard on-road driving, 4WD Part-Time for off-road use on higher traction surfaces, 4WD Full-Time for continuous four-wheel drive on varied or slippery surfaces, and 4WD Low (N) for extreme off-road situations requiring maximum torque and control.
Question 2: When should 4WD Part-Time be utilized, and what are its limitations?
4WD Part-Time should be engaged when additional traction is required, such as on snowy, icy, or unpaved surfaces. It should not be used on dry pavement as it can cause drivetrain binding and increased tire wear.
Question 3: How does 4WD Full-Time differ from 4WD Part-Time, and what are its benefits?
4WD Full-Time provides continuous power to all four wheels, automatically adjusting torque distribution based on traction needs via a viscous coupler. Unlike 4WD Part-Time, it can be used on dry pavement without causing drivetrain binding, offering enhanced stability in varied conditions.
Question 4: What distinguishes 4WD Low (N) from other modes, and when is its use appropriate?
4WD Low (N) provides the lowest gear ratio, maximizing torque for extreme off-road situations like rock crawling or deep mud/sand. The “N” denotes a neutral position within the transfer case, enabling flat towing. This mode is not suitable for higher speeds or paved roads.
Question 5: What is the role of the transfer case within the Selec-Trac system?
The transfer case is the core component of Selec-Trac, distributing power from the transmission to both axles. It contains the gearing necessary to facilitate different drive modes and is essential for transitioning between 2WD and 4WD.
Question 6: What are the maintenance requirements for the Selec-Trac system, specifically the transfer case?
Regular maintenance, including periodic fluid changes and inspections according to the manufacturer’s recommendations, is crucial for the transfer case’s longevity and optimal performance. Neglecting these maintenance requirements can lead to premature wear and potential failure.
Understanding these aspects of the Selec-Trac system is crucial for its proper utilization. Adhering to recommended operating procedures and maintenance schedules ensures optimal performance and longevity.
This concludes the FAQ section. The next section delves further into the mechanical intricacies of the Selec-Trac system.
Operational Tips for the Selec-Trac System in a Jeep Grand Cherokee (WJ)
Maximizing the effectiveness and lifespan of the Selec-Trac system requires adherence to specific operational guidelines. These recommendations ensure optimal performance and minimize potential mechanical issues.
Tip 1: Understand Mode Selection: Proper mode selection is paramount. 2WD maximizes fuel efficiency on paved roads. 4WD Part-Time suits off-road conditions with good traction. 4WD Full-Time offers enhanced stability on slippery surfaces. 4WD Low (N) is reserved for extreme off-road scenarios.
Tip 2: Respect Surface Suitability: Avoid using 4WD Part-Time on dry pavement. This can lead to drivetrain binding and accelerated tire wear. Reserve its use for low-traction surfaces like snow, mud, or loose gravel.
Tip 3: Shift-on-the-Fly Responsibly: While shift-on-the-fly allows transitions between 2WD and 4WD High while in motion, it should be executed smoothly and within the specified speed limit (up to 50 mph or 80 km/h). Avoid abrupt shifts.
Tip 4: Engage 4WD Low (N) Judiciously: 4WD Low (N) delivers maximum torque at very low speeds. Its use is restricted to extreme off-road conditions. Avoid engaging this mode on paved surfaces or at higher speeds to prevent drivetrain damage.
Tip 5: Monitor Transfer Case Fluid Levels: Regular inspection and maintenance of the transfer case fluid level are crucial. Refer to the owner’s manual for recommended fluid type and change intervals. Low fluid levels can lead to significant damage.
Tip 6: Heed Dashboard Indicators: Pay attention to dashboard indicators related to the four-wheel-drive system. Any illuminated warning lights should prompt immediate inspection and diagnosis by a qualified technician.
Tip 7: Avoid Excessive Speed in 4WD: While 4WD enhances traction, it’s essential to maintain safe and appropriate speeds, especially in off-road environments. Excessive speed in 4WD can lead to loss of control and potential vehicle damage.
Adhering to these operational guidelines significantly contributes to the longevity and reliable performance of the Selec-Trac system. Proper usage ensures the system functions as intended, maximizing its benefits across diverse driving conditions.
This operational guidance sets the stage for a concluding discussion on the overall significance and enduring relevance of the Selec-Trac system in the Jeep Grand Cherokee (WJ).
Selec-Trac
This exploration of the Selec-Trac system in the Jeep Grand Cherokee (WJ) has highlighted its key features, operational modes, and underlying mechanical principles. From the adaptability of shift-on-the-fly between 2WD and 4WD High, to the specialized low-range gearing of 4WD Low (N), the system’s versatility caters to diverse driving scenarios. The central role of the transfer case in distributing power and facilitating mode changes underscores its importance within the system’s architecture. Understanding the nuances of each mode 2WD, 4WD Part-Time, 4WD Full-Time, and 4WD Low (N) equips drivers to utilize the system effectively and responsibly. The specific implementation of Selec-Trac as Quadra-Trac II, with its automatic torque biasing via the gerotor coupling, further refines the WJ’s ability to adapt to changing traction conditions.
The Selec-Trac system remains a significant factor in the enduring appeal of the Jeep Grand Cherokee (WJ). Its combination of on-road drivability and off-road capability continues to attract drivers seeking a balance between everyday practicality and adventurous exploration. Continued understanding and proper maintenance of this system are essential for preserving its functionality and maximizing its lifespan, ensuring the WJ retains its versatile performance characteristics for years to come. The informed operation of Selec-Trac empowers drivers to fully exploit the WJ’s potential, solidifying its legacy as a capable and adaptable SUV.
