Three Unique 4 X 4 Systems Provide Command and Control and Cover the Marketplace
Industry-first Electronic Limited Slip Differentials – Front / Rear / Center
2005 Jeep Grand Cherokee is First Jeep Equipped with Electronic Transfer Case Engagement
The all-new 2005 Jeep® Grand Cherokee sets a new benchmark in the SUV market, combining legendary off-road capability with on-road driving manners through distinct 4 x 4 systems. It is available with three unique 4 x 4 systems – more than any of its competitors – giving customers the ability to choose what is best for their needs.
Innovations that the Jeep engineering team pioneered for this vehicle raise the off-road capabilities of Grand Cherokee even higher, while also improving the on-road driving manners of the vehicle, giving customers the balance they want for a vehicle that is just as comfortable in the urban jungle as it is in the Amazon.
The WK features an all-new aluminum Slip-in-Tube Propshaft that is designed so two pieces of the propshaft plunge into one another, eliminating the need for the slip and stud yokes typically required with conventional propshafts. The design solved vehicle NVH issues that competitor products could not by taking advantage of Slip-in-Tube’s inherent higher stiffness, lower mass and superior damping characteristics, enabling the new Grand Cherokee to be quieter than its replacement.
Quadra-Trac I is designed for Jeep Grand Cherokee owners who want the assurance of full-time all-wheel drive and no switches or levers to pull, the Quadra-Trac I is the right system. The system provides for smooth operation of the vehicle over a variety of road surface conditions. No driver interaction is required.
The NV140 transfer case splits torque 48/52 percent (front/rear) for nearly even distribution of engine power. The single-speed transfer case has been designed to rigorous Jeep durability standards while offering smooth and quiet operation. The use of Brake Traction Control System (BTCS) with the NV140 transfer case makes the 4 x 4 system extremely competent in a variety of situations. The BTC system provides resistance to any wheel that is slipping to allow additional torque transfer to wheels with traction.
Offering a single-speed transfer case attracts a new group of buyers to the Jeep Grand Cherokee lineup and builds on the capable, entry-level, two-wheel drive versions, which currently account for approximately 25 percent of Jeep vehicle sales.
The Quadra-Trac II 4 x 4 system gives owners the benefit of the NV245 active transfer case and BTCS. The transfer case is the same one used in the Quadra-Drive II system. It takes input from a variety of sensors to determine tire slip at the earliest possible moment and take corrective action. The system also uses Throttle Anticipate – sensing quick movement in throttle from a stop – and it takes steps to maximize traction before tire slippage even occurs.
Torque is transferred to the individual wheels as needed by the BTCS to maintain traction in changing road conditions. When the system senses tire slip, it modulates brake pressure to the slipping wheel, which directs torque to the tires with the best traction.
Quadra-Trac II features an electronic shift mechanism for ease-of-use. The transfer case also includes a neutral position for trouble-free towing behind another vehicle.
The Quadra-Drive II Jeep 4 x 4 system offers owners the ultimate in off-road capability. It combines the NV245 full-time transfer case with Electronic Limited Slip Differentials (ELSD) for best-in-class tractive performance. The system instantly detects tire slip and smoothly distributes engine torque to the tires with traction. In some cases, the vehicle will even anticipate low traction and adjust to proactively limit or eliminate slip
The heart of the system is the NV245 active transfer case. This transfer case includes a center differential coupled with an electronically controlled clutch pack, varying it from a completely open state to completely locked, and infinite possibilities in between. The 4-Low gear ratio is 2.72:1.
Quadra-Drive II features an electronic shift mechanism with a unique engagement lever. The lever is conveniently located on the shift console. Pulling the lever up engages 4-Low. The lever returns to a resting position after activation. The transfer case also includes a neutral position for trouble-free towing vehicles, such as behind a motor home.
A key component in the Quadra-Drive II system is the ELSD – an industry first application – and the new benchmark for automatic traction differentials. The ELSD use electronically controlled clutch packs to automatically and instantly vary from slip to lock at each axle. This maximizes traction when needed without any of the on-road drawbacks normally associated with such a robust 4 x 4 system.
All components of the system work together, continually monitoring needs, to provide smooth and automatic application of the components for best-in-class tractive performance while improving the day-to-day on-road driving experience. For example, the ELSD releases the clutch packs in the front axle during turns to allow differentiation and prevent crow hop.
Rear axle ELSD. The Eaton EGerodisctm is a hydraulically-operated electronically controlled limited slip differential that is capable of providing variable torque up to full axle lock
Quadra-Trac II / Quadra-Drive II
Operating Instructions and Precautions
This transfer case is fully automatic in the 4 HI mode. This transfer case divides engine torque almost evenly with 48 percent of engine torque to the front axle and 52 percent of engine torque to the rear axle. When speed differences are increased between the front and rear drive shafts, the transfer case can transmit up to 100 percent of available engine torque to the front or rear drive shafts.
When additional traction is required, the 4 LOW position can be used to lock the front and rear driveshafts together and force the front and rear wheels to rotate at the same speed. The 4 LOW position is intended for loose, slippery road surfaces only. Driving in the 4 LOW position on dry hard surfaced roads may cause increased tire wear and damage to driveline components.
When operating your vehicle in 4 LOW, the engine speed is approximately three times that of the 4 HI position at a given road speed. Take care not to overspeed the engine and do not exceed 25 mph (40 km/h).
Proper operation of four wheel drive vehicles depends on tires of equal size, type, and circumference on each wheel. Any difference will adversely affect shifting and cause damage to the transfer case.
Because four wheel drive provides improved traction, there is a tendency to exceed safe turning and stopping speeds. Do not go faster than road conditions permit.
Four Wheel Drive High Range – All roads surfaces such as ice, snow, gravel, sand, and dry hard pavement.
WARNING! You or others could be injured if you leave the vehicle unattended with the transfer case in the N (Neutral) position without first fully engaging the parking brake. The transfer case N (Neutral) position disengages both the front and rear driveshafts from the powertrain and will allow the vehicle to move regardless of the transmission position. The parking brake should always be applied when the driver is not in the vehicle.
Neutral – Disengages both the front and rear driveshafts from the powertrain. To be used for flat towing behind another vehicle. Refer to “Recreational Towing” in Section 5 of this manual.
Four Wheel Drive Low Range – Low speed 4 wheel drive. Locks the front and rear driveshafts together. Forces the front and rear wheels to rotate at the same speed. Additional traction and maximum pulling power for loose, slippery road surfaces only. Do not exceed 25 mph (40 km/h).
4 HI to 4 LOW
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h), key ON or engine running, shift the transmission into N (Neutral), and raise the transfer case T-handle. “The 4WD LOW Indicator Lamp” in the instrument cluster will begin to flash and remain on solid when the shift is complete. Release the T-handle.
NOTE: If shift conditions/interlocks are not met, or a transfer case motor temperature protection condition exists, a “CHECK SHIFT PROCEDURES” message will flash from the EVIC (Electronic Vehicle Information Center).
4 LOW to 4 Hi
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h), key ON or engine running, shift the transmission into N (Neutral), and raise the transfer case T-handle. The “4WD LOW Indicator Lamp” in the instrument cluster will flash and go out when the shift is complete. Release the T-handle.
NOTE: If shift conditions/interlocks are not met, or a transfer case motor temperature protection condition exists, a “CHECK SHIFT PROCEDURES” message will flash from the EVIC.
NOTE: Shifting into or out of 4WD LOW is possible with the vehicle completely stopped, however difficulty may occur due to the mating clutch teeth not being properly aligned. Several attempts may be required for clutch teeth alignment and shift completion to occur. The preferred method is with the vehicle rolling 0 to 3 mph (0 to 5 km/h). If the vehicle is moving faster than 3 mph (5 km/h), the transfer case will not allow the shift.
Neutral (N) Shift Procedure
1. Key ON, engine off.
2. Vehicle stopped, with foot on brake.
3. Place transmission in N (Neutral).
4. Hold down N (Neutral) “pin” switch (with a pen, etc.) for 4 seconds until the LED lamp by the switch starts to blink indicating shift in progress. Lamp will stop blinking (stay on solid) when Neutral shift is complete. A “4WD SYSTEM IN NEUTRAL” message will display on the EVIC.
5. Repeat Steps 1- 4 to shift out of Neutral.
NOTE: If shift conditions/interlocks are not met, a “CHECK SHIFT PROCEDURES” message will flash from the EVIC.
The optional Quadra-Drive” System, available only on Limited models, features three torque transfer couplings. The couplings include ELSE (Electronic Limited Slip Differential) front and rear axles and Quadra-Trac II® transfer case. The optional ELSE axles are fully automatic and require no driver input to operate. Under normal driving conditions the units function as standard axles balancing torque evenly between left and right wheels. With a traction difference between left and right wheels the coupling will sense a speed difference. As one wheel begins to spin faster than the other, torque will automatically transfer from the wheel that has less traction to the wheel that has traction.
While the transfer case and axle couplings differ in design, their operation is similar. Follow the Quadra-Trac II transfer case shifting information above for shifting this system.
WK off-road driving tips from Jeep
NOTE: Prior to off-road driving, remove the front air dam to prevent damage. The front air dam is attached to the lower front fascia with quarter turn fasteners, and can be removed by hand.
When To Use 4WD LOW Range
When off-road driving, shift to 4WD LOW for additional traction. This range should be limited to extreme situations such as deep snow, mud, or sand where additional low speed pulling power is needed. Vehicle speeds in excess of 25 mph (40 km/h) should be avoided when in 4WD LOW range.
Driving Through Water
Although your vehicle is capable of driving through water, there are a number of precautions that must be considered before entering the water:
CAUTION! When driving through water, do not exceed 5 mph (8 km/h). Always check water depth before entering as a precaution, and check all fluids afterward. Driving through water may cause damage that may not be covered by the new vehicle limited warranty. Driving through water more than a few inches deep will I require extra caution to ensure safety and prevent damage to your vehicle. If you must drive through water, try to determine the depth and the bottom condition (and location of any obstacles) prior to entering. Proceed with caution and maintain a steady controlled speed less than 5 mph (8 km/h) in deep water to minimize wave effects.
If the water is swift flowing and rising (as in storm run-off) avoid crossing until the water level recedes and/or the flow rate is reduced. If you must cross flowing water avoid depths in excess of 9 inches. The flowing water can erode the streambed causing your vehicle to sink into deeper water. Determine exit point(s) that are downstream of your entry point to allow for drifting.
Avoid driving in standing water deeper than 20 inches, and reduce speed appropriately to minimize wave effects. Maximum speed in 20 inches of water is less than 5 mph (8 km/h).
After driving through deep water, inspect your vehicle fluids and lubricants (engine oil, transmission oil, axle, transfer case) to assure the fluids have not been contaminated. Contaminated fluid (milky, foamy in appearance) should be flushed/changed as soon as possible to prevent component damage.
Driving In Snow, Mud and Sand
In heavy snow, when pulling a load, or for additional control at slower speeds, shift the transmission to a low gear and shift the transfer case to 4WD LOW if necessary. Refer to “Four-Wheel Drive Operation” above. Do not shift to a lower gear than necessary to maintain headway. Over-revving the engine can spin the wheels and traction will be lost.
Avoid abrupt downshifts on icy or slippery roads, because engine braking may cause skidding and loss of control.
NOTE: Before attempting to climb a hill, determine the conditions at the crest and/or on the other side.
Before climbing a steep hill, shift the transmission to a lower gear and shift the transfer case to 4WD LOW. Use first gear and 4WD LOW for very steep hills.
If you stall or begin to lose headway while climbing a steep hill, allow your vehicle to come to a stop and immediately apply the brakes. Restart the engine and shift to R (Reverse). Back slowly down the hill allowing the compression braking of the engine to help regulate your speed. If the brakes are required to control vehicle speed, apply them lightly and avoid locking or skidding the tires.
WARNING! If the engine stalls or you lose headway or cannot make it to the top of a steep hill or grade, never attempt to turn around. To do so may result in tipping and rolling the vehicle. Always back carefully straight down a hill in R (Reverse) gear. Never back down a hill in N (Neutral) using only the brake.
Remember, never drive diagonally across a hill-always drive straight up or down. If the wheels start to slip as you approach the crest of a hill, ease off the accelerator and maintain headway by turning the front wheels slowly. This may provide a fresh “bite” into the surface and will usually provide traction to complete the climb.
Shift the transmission into a low gear and the transfer case to 4WD LOW range. Let the vehicle go slowly down the hill with all four wheels turning against engine compression drag. This will permit you to control the vehicle speed and direction. When descending mountains or hills, repeated braking can cause brake fade with loss of braking control. Avoid repeated heavy braking by downshifting the transmission whenever possible.
After Driving Off-Road
Off-road operation puts more stress on your vehicle than does most on-road driving. After going off-road it is always a good idea to check for damage. That way you can get any problems taken care of right away and have your vehicle ready when you need it .
Completely inspect the underbody of your vehicle. Check tires, body structure, steering, suspension, and exhaust system for damage.
Check threaded fasteners for looseness, particularly on the chassis, drivetrain components, steering, and suspension. Retighten them, if required, and torque to the values specified in the Service Manual.
Check for accumulations of plants or brush. These things could be a fire hazard. They might hide damage to fuel lines, brake hoses, axle pinion seals, and propeller shafts.
After extended operation in mud, sand, water, or similar dirty conditions, have brake rotors, wheels, brake linings, and axle yokes inspected and cleaned as soon as possible.
WARNING! Abrasive material in any part of the brakes may cause excessive wear or unpredictable braking. You might not have full braking power when you need it to prevent an accident. If you have been operating your vehicle in dirty conditions, get your brakes checked and cleaned as necessary.
If you experience unusual vibration after driving in mud, slush or similar conditions, check the wheels for impacted material. Impacted material can cause a wheel imbalance and freeing the wheels of it will correct the situation.