Jeep four wheel drive systems
Encyclopedia
Jeep
uses a variety of four-wheel drive
and all-wheel drive systems on their various vehicles
. These range from basic part-time systems that require the driver to move a control lever to send power to four wheels, to permanent four-wheel systems that monitor and sense traction needs at all four wheels automatically under all conditions.
The makers of Jeep transfer cases are include Dana, Borg-Warner, as well as either New Process (NP) or New Venture Gear
(NV) as indicated by the model numbers.
Applications:
The Dana 20 part-time gear system. It is similar to the Dana 18 except that the rear output shaft is centered. This enables 2-wheel High to be direct-drive, which is quieter. Otherwise the Dana 20 offers the same drive modes as the Dana 18.
Applications:
The Dana 21 part-time gear system with single-speed case with automatic transmission. The Dana 21 is essentially a Dana 20 without a Low range (only 2-wheel High and Part-time 4-wheel High).
Applications:
The Dana 300 part-time gear system.
Applications:
More commonly, Command-Trac is used to refer to the NP/NV-231 or NP-207 transfer cases introduced along with the Jeep Cherokee
(XJ) in 1984. The system offers a chain-driven, aluminum, "shift-on-the-fly" transfer case. The "shift-on-the-fly" feature provides manual ease and assist while engaging 4WD. Command-Trac should only be driven in 4WD on low-traction surfaces due to the front and rear axles being locked together (no differential action in the transfer case). Driving in 4WD on dry pavement causes excessive wheel and drivetrain wear. Four-wheel modes are most commonly used for wet/slick surfaces or extreme weather conditions (rain, snow, etc.) (4H), towing (N), and off-road activities (4L).
There are reports of a modified version known as NP-231J HD which was supposedly (SP) a "heavy duty" version for the Jeep Grand Cherokee ZJ
with V8 engines. The NP/NV-231 case is a chain-driven unit that takes 21- or 23-spline input shafts. The 23-spline was for the AX-15 transmission, and the 21-spline was used for the AX-5 and BA 10/5 transmissions. Low range for this case was 2.72 and high range was 1.00.
The Command-Trac HD transfer case was used in 6-speed Liberty KJ's from 2005–2007. Although sometimes referred to as the "NV(NP)231HD," the transfer cases are actually the 241 series used in full-sized trucks from other makers (241D or 241C). The Jeep version is labelled "NV(NP)241J." This is not the NV241OR transfer case found in the Jeep Wrangler Rubicon, which uses a 4.0 low range and has a reinforced case. Dodge uses a 241DHD, which has a reinforced case but the 2.72 low-range.
The Jeep Grand Cherokee/Commander line no longer offers a part-time transfer case option. The reason behind this was its poor sales along with an improved Selec-Trac. Selec-Trac and a simplistic Quadra-Trac had the convenience and comfort of "Full-Time" all wheel drive that Command-Trac lacked for "luxury" SUV's that did not require the more rugged part-time system.
The terms "Command-Trac" and "Selec-Trac" where used in other Jeep lines and refer to different transfer cases in those lines.
Applications:
The NP228 Selec-Trac transfer case is closely related to the NP229. The only difference is that the NP228 does not have limited-slip when in 4Hi full-time. It was used briefly in 1986.
The NP242 Selec-Trac transfer case debuted with the compact Jeep Cherokee in 1984, borrowed from the AMC Eagle
. It is a more common feature in the upscale version Jeep Wagoneer
(XJ), and Dodge Durango models (1998-present). It has a shift-on-the-fly transfer-case like Command-Trac but unlike it, Selec-Trac offers full-time all wheel drive in addition to the part-time 4WD of Command-Trac. Full-Time all wheel drive has the ability for the front and rear axles to rotate at different speeds, making driving on dry and wet surfaces possible year-round without shifting back to 2WD again. It still has the ability to lock the front and rear axles.
Other Jeep vehicles used Selec-Trac, for example, the Jeep Grand Cherokee
, before being discontinued on that platform in favor of the electronically controlled Quadra-Drive II AWD system in 2005. Selec-Trac is currently only available for the Jeep Liberty lineup.
Selec-Trac uses the New Venture Gear
NV242 transfer case (formerly known as NP242).
Applications:
The Quadra-Trac name is used on a variety of full-time 4WD systems. The first version was launched in 1973, the Borg-Warner BW 1339. An unrelated system was used in the 1980s. Yet another system carried the name in the 1990s.
Quadra-Trac was the trade name for the Borg-Warner 1305 and 1339 gear case. It was a chain-drive system introduced in 1973 on the full-sized Jeep line which included the Wagoneer, Cherokee, and trucks behind the AMC-specific Turbo-Hydramatic 400 automatic transmission. CJ7s also received the Quadra-trac. This system included a differential to shift torque between front and rear which could be locked with vacuum. The 1305 lacked a low-range, while the 1339 offered an optional 2.57 planetary gear. A Quadratrac transfer case can be upgraded from a non low range equipped unit to having low range by swapping in the optional planetary housing and shift rod and floor shifter assembly from another transfer case. Consult a factory service manual for service procedures.
The Borg-Warner 1305 offered only 4WD Hi modes in full-time or part-time (locked) modes. With the low range the BW 1339 offered four modes: 4HI FT, 4HIPT, 4LO FT, and 4LO PT.
The NP219 Quadratrac transfer case was used in full-size Jeeps from 1980 through 1982. It offered the following modes: 4HiFT, 4HiPT, and 4LoPT. In full-time 4WD High a viscous-type limited-slip coupling is used between the front and rear output shafts.
The Jeep Quadra-Trac was differentiated from the open "New Process" Gear NP203 used by Dodge
, General Motors, and Ford
in that it included a center limited slip differential feature, in this case a clutch pack.
The part-time case available in these vehicle at this time was the Dana 20.
Applications:
The Borg-Warner system was replaced with a "New Process Gear" NP219-based chain-driven system in 1980
Applications:
The NP229-based system "New Process Gear" was replaced with a New Venture Gear
NV249-based chain-driven system in 1996.
The NP249/NV249 utilizes a "Viscous Coupler" to determine power transfer between the front and rear axles. The goal of this device is to provide smooth and efficient 4WD operation on dry surfaces — if a differential in speed occurs between the axles, heat buildup in the viscous coupler transfers power to the slower axle, providing some traction in off road conditions. Splitting the torque to the front and rear, it is similar to several passenger car systems, but with a low-range gear for serious off-roading.
1993-1995 NP249 transfer cases used the viscous coupler to transfer power in both high and low ranges.
1996-1998 NV249 transfer cases had a low-lock capability, meaning a hard gear transferred power in 4LO (front and rear drive shafts are locked at same speed in low range).
Applications:
NV247 transfer case. This two-speed chain-driven transfer case uses a gerotor
, a clutch pack coupled to a hydraulic pump, to transfer torque between the front and rear axles. The transfer case contains three modes, 4-All Time, Neutral, and 4-Lo. In 4-All Time, torque is applied to the rear wheels under normal driving conditions. If the rear axle starts spinning at a higher rate than the front axle, hydraulic pressure builds up in the gerotor and causes the clutch pack to progressively transfer torque to the axle with more traction until both axles return to the same speed. Neutral mode is intended for towing the vehicle. In 4-Lo, the front and rear axles are locked together through a 2.72 reduction gear ratio.
In Quadra-Drive, the NV247 transfer case is mated to front and rear axles containing Jeep's Vari-Lok differentials. Vari-Lok differentials also use a gerotor to transfer torque.
Applications:
Applications:
NV147 transfer case, a version of the NV247 transfer case lacking neutral and low-range modes.
Applications:
NV245 transfer case mated to front and rear electronic limited slip differential. It includes a Neutral mode and utilizes a 2.72 reduction gear ratio in low-range.
Applications:
NV245 transfer case without Quadra-Drive's ELSDs.
Applications:
Applications:
's four wheel drive
system used in its compact crossover SUV
s based on a front wheel drive platform, the Compass
and Patriot
. There are two versions of the basic Freedom Drive system for the US Market, called I and II.
Applications:
to simulate the benefits of a 19:1 low-range transfer case for off-road use. This function is an alternate program in the CVT and is not a transfer case function. FDII also adds hill descent control system
, off-road tuned traction control
, and electronic stability program. The Patriot with FDII also feature longer suspension travel, skid plates, tow hooks, and a full-size spare tire. This enables the FDII-equipped Patriot to wear the "Trail Rated" badge from Jeep. Trail Rated Jeep vehicles are determined by meeting several requirements of off-road conditions including water fording, articulation, and other tests.
Applications:
For the European Market there is a single version which combines elements of both U.S. versions. The European version is available with either a CVT gearbox or most commonly with a 6-speed manual gearbox and has two settings on the traction control and electronic stability program systems to cater for off-road activity, U.S. FDII suspension travel and a full-size spare tire. Skid plates and tow hooks are options in the EU, but the hill descent control system is not available.
Applications:
Jeep
Jeep is an automobile marque of Chrysler . The first Willys Jeeps were produced in 1941 with the first civilian models in 1945, making it the oldest off-road vehicle and sport utility vehicle brand. It inspired a number of other light utility vehicles, such as the Land Rover which is the second...
uses a variety of four-wheel drive
Four-wheel drive
Four-wheel drive, 4WD, or 4×4 is a four-wheeled vehicle with a drivetrain that allows all four wheels to receive torque from the engine simultaneously...
and all-wheel drive systems on their various vehicles
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
. These range from basic part-time systems that require the driver to move a control lever to send power to four wheels, to permanent four-wheel systems that monitor and sense traction needs at all four wheels automatically under all conditions.
The makers of Jeep transfer cases are include Dana, Borg-Warner, as well as either New Process (NP) or New Venture Gear
New Venture Gear
New Venture Gear, a division of Magna Powertrain, is a automobile transmission company. It was founded in 1888 under the name "New Process Gear" then in 1934 it was purchased by Walter Chrysler. In 1999 New Process Gear was renamed "New Venture Gear" when it became a joint venture between General...
(NV) as indicated by the model numbers.
Dana
The Dana 18 part-time gear system. It uses a cast iron case and both the front and rear output shafts are offset towards the passenger side of the vehicle. Drive modes offered include 2-wheel High, Part-time 4-wheel High, and Part-time 4-wheel Low.Applications:
- Jeep CJJeep CJThe Willys CJ is a public version of the famous Willys Military Jeep from World War II.The first CJ prototype was introduced in 1944 by Willys, and the same basic vehicle stayed in production through seven variants and three corporate parents until 1986.A variant of the CJ is still in production...
, Jeep Forward ControlJeep Forward ControlThe Jeep Forward Control is a truck that was produced by Willys and then Kaiser Jeep from 1956 to 1965. It was also assembled in other international markets. The layout featured a cab over design.- Design :...
, Willys Jeep WagonWillys Jeep WagonThe Willys Jeep Station Wagon, introduced in 1946 by Willys-Overland Motors is the first mass-market all-steel station wagon designed and built as a passenger vehicle and is arguably the world's first popular sport utility vehicle or SUV The Willys Jeep Station Wagon, introduced in 1946 by...
, Willys Jeep TruckWillys Jeep TruckThe 4-wheel drive Willys Jeep Truck, introduced in 1947 by Willys-Overland Motors, was similar to the Willys Jeep Station Wagon and the VJ-2 and VJ-3 Willys Jeepster. With model designations of 2T and 4T, these trucks were equipped with the 134 cubic inch Go-Devil flathead four-cylinder engine...
(1941-1971)
The Dana 20 part-time gear system. It is similar to the Dana 18 except that the rear output shaft is centered. This enables 2-wheel High to be direct-drive, which is quieter. Otherwise the Dana 20 offers the same drive modes as the Dana 18.
Applications:
- Jeep CJJeep CJThe Willys CJ is a public version of the famous Willys Military Jeep from World War II.The first CJ prototype was introduced in 1944 by Willys, and the same basic vehicle stayed in production through seven variants and three corporate parents until 1986.A variant of the CJ is still in production...
, Jeep SJJeep SJJeep's SJ platform was part of the "FSJ" or full-size Jeep lineup. According to the , an "FSJ" is any vehicle produced in North America, carrying the "Jeep" nameplate, with 2 or 4 doors, in rear or four wheel drive, whose wheelbase does not exceed , nor is less than , and whose tread width is no...
(full size), Jeepster, (1963-1979)
The Dana 21 part-time gear system with single-speed case with automatic transmission. The Dana 21 is essentially a Dana 20 without a Low range (only 2-wheel High and Part-time 4-wheel High).
Applications:
- Jeep SJJeep SJJeep's SJ platform was part of the "FSJ" or full-size Jeep lineup. According to the , an "FSJ" is any vehicle produced in North America, carrying the "Jeep" nameplate, with 2 or 4 doors, in rear or four wheel drive, whose wheelbase does not exceed , nor is less than , and whose tread width is no...
(full size Wagoneer, Cherokee, Pickup truck) (1963-1969)
The Dana 300 part-time gear system.
Applications:
- Jeep CJJeep CJThe Willys CJ is a public version of the famous Willys Military Jeep from World War II.The first CJ prototype was introduced in 1944 by Willys, and the same basic vehicle stayed in production through seven variants and three corporate parents until 1986.A variant of the CJ is still in production...
(1980-1986)
Command-Trac
Command-Trac was first introduced using the NP208 transfer case in the full-size Jeeps (SJ series) in 1980. The drive modes are the same as with the Dana 18 and 20 transfer cases: 2Hi, 4HI PT, and 4LO PT. The 4WD modes are not for use on high-traction surfaces such as dry roads. The NP208 was used through at least 1987.More commonly, Command-Trac is used to refer to the NP/NV-231 or NP-207 transfer cases introduced along with the Jeep Cherokee
Jeep Cherokee (XJ)
The Jeep Cherokee is a unibody compact SUV. It shared the name of the original full-size SJ model, but without a body-on-frame chassis, it set the stage for the modern SUV. Its innovative appearance and sales popularity spawned important imitators as other automakers began to notice that this...
(XJ) in 1984. The system offers a chain-driven, aluminum, "shift-on-the-fly" transfer case. The "shift-on-the-fly" feature provides manual ease and assist while engaging 4WD. Command-Trac should only be driven in 4WD on low-traction surfaces due to the front and rear axles being locked together (no differential action in the transfer case). Driving in 4WD on dry pavement causes excessive wheel and drivetrain wear. Four-wheel modes are most commonly used for wet/slick surfaces or extreme weather conditions (rain, snow, etc.) (4H), towing (N), and off-road activities (4L).
There are reports of a modified version known as NP-231J HD which was supposedly (SP) a "heavy duty" version for the Jeep Grand Cherokee ZJ
Jeep Grand Cherokee
The Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
with V8 engines. The NP/NV-231 case is a chain-driven unit that takes 21- or 23-spline input shafts. The 23-spline was for the AX-15 transmission, and the 21-spline was used for the AX-5 and BA 10/5 transmissions. Low range for this case was 2.72 and high range was 1.00.
The Command-Trac HD transfer case was used in 6-speed Liberty KJ's from 2005–2007. Although sometimes referred to as the "NV(NP)231HD," the transfer cases are actually the 241 series used in full-sized trucks from other makers (241D or 241C). The Jeep version is labelled "NV(NP)241J." This is not the NV241OR transfer case found in the Jeep Wrangler Rubicon, which uses a 4.0 low range and has a reinforced case. Dodge uses a 241DHD, which has a reinforced case but the 2.72 low-range.
The Jeep Grand Cherokee/Commander line no longer offers a part-time transfer case option. The reason behind this was its poor sales along with an improved Selec-Trac. Selec-Trac and a simplistic Quadra-Trac had the convenience and comfort of "Full-Time" all wheel drive that Command-Trac lacked for "luxury" SUV's that did not require the more rugged part-time system.
The terms "Command-Trac" and "Selec-Trac" where used in other Jeep lines and refer to different transfer cases in those lines.
Applications:
- Jeep CherokeeJeep Cherokee (XJ)The Jeep Cherokee is a unibody compact SUV. It shared the name of the original full-size SJ model, but without a body-on-frame chassis, it set the stage for the modern SUV. Its innovative appearance and sales popularity spawned important imitators as other automakers began to notice that this...
(XJ) 1984–2001 - Jeep ComancheJeep ComancheThe Jeep Comanche is a pickup truck version of the Cherokee compact SUV that was produced from 1985 to 1992. Rear wheel and four-wheel drive models were available, as well as two cargo box lengths of six-feet or seven-feet .-Introduction:During the mid-1980s, according to AMC Chairman W...
(MJ) 1986–1992 - Jeep WranglerJeep WranglerThe Jeep Wrangler is a subcompact four-wheel drive sport utility vehicle and an off-road vehicle manufactured by American automaker Chrysler, under its Jeep marque – and now in its fourth generation. It is a successor to the famous World War II 'Jeep' vehicle by way of the Willys civilian...
(YJ, TJ, JK) 1987–Present - Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(ZJ) 1993–1995 - Jeep LibertyJeep LibertyInspired by styling from the Dakar and Jeepster concept cars, the Liberty was intended as a replacement for the discontinued Jeep Cherokee . Three trim levels were initially offered; the top end Limited, a more rugged looking Renegade and the base Sport. All were made available with either 2WD or 4WD...
(KJ, KK) 2002–Present - Jeep Wagoneer/Grand Wagoneer (SJ) 1980-1987
Selec-Trac
Selec-Trac was introduced in the full-size Jeeps in 1983 using the NP229 transfer case. The NP229 offered three modes: 2Hi, 4Hi full-time using a viscous-type limited-slip coupling, and 4Lo Locked. It was used from 1983 to 1991 in some applications.The NP228 Selec-Trac transfer case is closely related to the NP229. The only difference is that the NP228 does not have limited-slip when in 4Hi full-time. It was used briefly in 1986.
The NP242 Selec-Trac transfer case debuted with the compact Jeep Cherokee in 1984, borrowed from the AMC Eagle
AMC Eagle
The AMC Eagle is a compact-sized four-wheel drive passenger vehicle that was produced by American Motors Corporation . The AMC Eagle line of vehicles inaugurated a new product category of "sport-utility" or crossover SUV....
. It is a more common feature in the upscale version Jeep Wagoneer
Jeep Wagoneer
The Jeep Wagoneer was an early sport utility vehicle and the first luxury 4x4, produced under varying marques from 1963 to 1991. It was noteworthy for being in production for more than 28 years with only minor mechanical changes...
(XJ), and Dodge Durango models (1998-present). It has a shift-on-the-fly transfer-case like Command-Trac but unlike it, Selec-Trac offers full-time all wheel drive in addition to the part-time 4WD of Command-Trac. Full-Time all wheel drive has the ability for the front and rear axles to rotate at different speeds, making driving on dry and wet surfaces possible year-round without shifting back to 2WD again. It still has the ability to lock the front and rear axles.
Other Jeep vehicles used Selec-Trac, for example, the Jeep Grand Cherokee
Jeep Grand Cherokee
The Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
, before being discontinued on that platform in favor of the electronically controlled Quadra-Drive II AWD system in 2005. Selec-Trac is currently only available for the Jeep Liberty lineup.
Selec-Trac uses the New Venture Gear
New Venture Gear
New Venture Gear, a division of Magna Powertrain, is a automobile transmission company. It was founded in 1888 under the name "New Process Gear" then in 1934 it was purchased by Walter Chrysler. In 1999 New Process Gear was renamed "New Venture Gear" when it became a joint venture between General...
NV242 transfer case (formerly known as NP242).
Applications:
- Jeep CherokeeJeep Cherokee (XJ)The Jeep Cherokee is a unibody compact SUV. It shared the name of the original full-size SJ model, but without a body-on-frame chassis, it set the stage for the modern SUV. Its innovative appearance and sales popularity spawned important imitators as other automakers began to notice that this...
(XJ) 1984–2001 - Jeep WagoneerJeep Cherokee (XJ)The Jeep Cherokee is a unibody compact SUV. It shared the name of the original full-size SJ model, but without a body-on-frame chassis, it set the stage for the modern SUV. Its innovative appearance and sales popularity spawned important imitators as other automakers began to notice that this...
(XJ) 1984–1990 - Jeep ComancheJeep ComancheThe Jeep Comanche is a pickup truck version of the Cherokee compact SUV that was produced from 1985 to 1992. Rear wheel and four-wheel drive models were available, as well as two cargo box lengths of six-feet or seven-feet .-Introduction:During the mid-1980s, according to AMC Chairman W...
(MJ) 1986–1992 - Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(ZJ, WJ) 1993–2004 - Jeep LibertyJeep LibertyInspired by styling from the Dakar and Jeepster concept cars, the Liberty was intended as a replacement for the discontinued Jeep Cherokee . Three trim levels were initially offered; the top end Limited, a more rugged looking Renegade and the base Sport. All were made available with either 2WD or 4WD...
(KJ) 2002–Present - Dodge DurangoDodge DurangoThe Dodge Durango is a full-size crossover SUV from the Dodge division of Chrysler. It was introduced in 1998 as a mid-size SUV, and as a replacement for the Ramcharger discontinued in the North American market in 1993, and was redesigned to full-size for 2004....
1998-Present - Jeep Grand Wagoneer Option on many models
Quadra-Trac
Quadra-Trac was the trade name for the Borg-Warner 1305 and 1339 gear case. It was a chain-drive system introduced in 1973 on the full-sized Jeep line which included the Wagoneer, Cherokee, and trucks behind the AMC-specific Turbo-Hydramatic 400 automatic transmission. CJ7s also received the Quadra-trac. This system included a differential to shift torque between front and rear which could be locked with vacuum. The 1305 lacked a low-range, while the 1339 offered an optional 2.57 planetary gear. A Quadratrac transfer case can be upgraded from a non low range equipped unit to having low range by swapping in the optional planetary housing and shift rod and floor shifter assembly from another transfer case. Consult a factory service manual for service procedures.
The Borg-Warner 1305 offered only 4WD Hi modes in full-time or part-time (locked) modes. With the low range the BW 1339 offered four modes: 4HI FT, 4HIPT, 4LO FT, and 4LO PT.
The NP219 Quadratrac transfer case was used in full-size Jeeps from 1980 through 1982. It offered the following modes: 4HiFT, 4HiPT, and 4LoPT. In full-time 4WD High a viscous-type limited-slip coupling is used between the front and rear output shafts.
The Jeep Quadra-Trac was differentiated from the open "New Process" Gear NP203 used by Dodge
Dodge
Dodge is a United States-based brand of automobiles, minivans, and sport utility vehicles, manufactured and marketed by Chrysler Group LLC in more than 60 different countries and territories worldwide....
, General Motors, and Ford
Ford Motor Company
Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...
in that it included a center limited slip differential feature, in this case a clutch pack.
The part-time case available in these vehicle at this time was the Dana 20.
Applications:
- Jeep WagoneerJeep WagoneerThe Jeep Wagoneer was an early sport utility vehicle and the first luxury 4x4, produced under varying marques from 1963 to 1991. It was noteworthy for being in production for more than 28 years with only minor mechanical changes...
1973–1979 - Jeep CherokeeJeep Cherokee (SJ)The SJ series Jeep Cherokee was a full-size SUV produced from 1974 through 1983 by the Jeep division of the American Motors Corporation...
1973–1979 - Jeep GladiatorJeep GladiatorThe Jeep Gladiator is a full-size pickup truck based on the large SJ platform that was built under varying marques from 1962 to 1988. The Jeep pickup design was noteworthy for being in production for more than 26 years with only minor mechanical changes...
1973–1979 - Jeep CJ-7Jeep CJThe Willys CJ is a public version of the famous Willys Military Jeep from World War II.The first CJ prototype was introduced in 1944 by Willys, and the same basic vehicle stayed in production through seven variants and three corporate parents until 1986.A variant of the CJ is still in production...
1976–1979
The Borg-Warner system was replaced with a "New Process Gear" NP219-based chain-driven system in 1980
Applications:
- Jeep WranglerJeep WranglerThe Jeep Wrangler is a subcompact four-wheel drive sport utility vehicle and an off-road vehicle manufactured by American automaker Chrysler, under its Jeep marque – and now in its fourth generation. It is a successor to the famous World War II 'Jeep' vehicle by way of the Willys civilian...
1987 - Jeep CherokeeJeep Cherokee (XJ)The Jeep Cherokee is a unibody compact SUV. It shared the name of the original full-size SJ model, but without a body-on-frame chassis, it set the stage for the modern SUV. Its innovative appearance and sales popularity spawned important imitators as other automakers began to notice that this...
(XJ) 1984–1987
The NP229-based system "New Process Gear" was replaced with a New Venture Gear
New Venture Gear
New Venture Gear, a division of Magna Powertrain, is a automobile transmission company. It was founded in 1888 under the name "New Process Gear" then in 1934 it was purchased by Walter Chrysler. In 1999 New Process Gear was renamed "New Venture Gear" when it became a joint venture between General...
NV249-based chain-driven system in 1996.
The NP249/NV249 utilizes a "Viscous Coupler" to determine power transfer between the front and rear axles. The goal of this device is to provide smooth and efficient 4WD operation on dry surfaces — if a differential in speed occurs between the axles, heat buildup in the viscous coupler transfers power to the slower axle, providing some traction in off road conditions. Splitting the torque to the front and rear, it is similar to several passenger car systems, but with a low-range gear for serious off-roading.
1993-1995 NP249 transfer cases used the viscous coupler to transfer power in both high and low ranges.
1996-1998 NV249 transfer cases had a low-lock capability, meaning a hard gear transferred power in 4LO (front and rear drive shafts are locked at same speed in low range).
Applications:
- Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(ZJ) 1993–1998
Quadra-Drive (WJ)
Quadra-Drive employed the New Venture GearNew Venture Gear
New Venture Gear, a division of Magna Powertrain, is a automobile transmission company. It was founded in 1888 under the name "New Process Gear" then in 1934 it was purchased by Walter Chrysler. In 1999 New Process Gear was renamed "New Venture Gear" when it became a joint venture between General...
NV247 transfer case. This two-speed chain-driven transfer case uses a gerotor
Gerotor
A gerotor is a positive displacement pumping unit. The name gerotor is derived from "Generated Rotor". A gerotor unit consists of an inner and outer rotor. The inner rotor has N teeth, and the outer rotor has N+1 teeth. The inner rotor is located off-center and both rotors rotate...
, a clutch pack coupled to a hydraulic pump, to transfer torque between the front and rear axles. The transfer case contains three modes, 4-All Time, Neutral, and 4-Lo. In 4-All Time, torque is applied to the rear wheels under normal driving conditions. If the rear axle starts spinning at a higher rate than the front axle, hydraulic pressure builds up in the gerotor and causes the clutch pack to progressively transfer torque to the axle with more traction until both axles return to the same speed. Neutral mode is intended for towing the vehicle. In 4-Lo, the front and rear axles are locked together through a 2.72 reduction gear ratio.
In Quadra-Drive, the NV247 transfer case is mated to front and rear axles containing Jeep's Vari-Lok differentials. Vari-Lok differentials also use a gerotor to transfer torque.
Applications:
- Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(WJ) 1999–2004
Quadra-Trac II (WJ)
Quadra-Trac II also employed the NV247 transfer case but lacked Quadra-Drive's front and rear Vari-Lok differentials.Applications:
- Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(WJ) 1999–2004
Quadra-Trac I (WJ)
Quadra-Trac I consisted of the New Venture GearNew Venture Gear
New Venture Gear, a division of Magna Powertrain, is a automobile transmission company. It was founded in 1888 under the name "New Process Gear" then in 1934 it was purchased by Walter Chrysler. In 1999 New Process Gear was renamed "New Venture Gear" when it became a joint venture between General...
NV147 transfer case, a version of the NV247 transfer case lacking neutral and low-range modes.
Applications:
- Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(WJ) 2004
Quadra-Drive II (WK, XK)
Quadra-Drive II consists of the New Venture GearNew Venture Gear
New Venture Gear, a division of Magna Powertrain, is a automobile transmission company. It was founded in 1888 under the name "New Process Gear" then in 1934 it was purchased by Walter Chrysler. In 1999 New Process Gear was renamed "New Venture Gear" when it became a joint venture between General...
NV245 transfer case mated to front and rear electronic limited slip differential. It includes a Neutral mode and utilizes a 2.72 reduction gear ratio in low-range.
Applications:
- Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(WK) 2005–2010 - Jeep CommanderJeep CommanderThe Jeep Commander is a mid size SUV produced from 2006 to 2010. The first use of the Commander name on a passenger vehicle was the popular Studebaker Commander which was produced from the 1920s through 1966....
(XK) 2006–2010
Quadra-Trac II (WK, XK)
Quadra-Trac II consists of the New Venture GearNew Venture Gear
New Venture Gear, a division of Magna Powertrain, is a automobile transmission company. It was founded in 1888 under the name "New Process Gear" then in 1934 it was purchased by Walter Chrysler. In 1999 New Process Gear was renamed "New Venture Gear" when it became a joint venture between General...
NV245 transfer case without Quadra-Drive's ELSDs.
Applications:
- Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(WK) 2005–2009 - Jeep CommanderJeep CommanderThe Jeep Commander is a mid size SUV produced from 2006 to 2010. The first use of the Commander name on a passenger vehicle was the popular Studebaker Commander which was produced from the 1920s through 1966....
(XK) 2006–2009
Quadra-Trac I (WK, XK)
Quadra-Trac I consists of the NV1240 transfer case, a version of the NV245 transfer case lacking neutral and low-range modes.Applications:
- Jeep Grand CherokeeJeep Grand CherokeeThe Jeep Grand Cherokee is a Mid-size SUV produced by the Jeep division of Chrysler. While some other SUVs were manufactured with body on frame construction, the Jeep Grand Cherokee has always used a unibody chassis.- Development :...
(WK) 2005-2010 - Jeep CommanderJeep CommanderThe Jeep Commander is a mid size SUV produced from 2006 to 2010. The first use of the Commander name on a passenger vehicle was the popular Studebaker Commander which was produced from the 1920s through 1966....
(XK) 2006–2010
Jeep BTCS
ALL 4WD systems in the WK come coupled with Jeep's brake traction control system (BTCS).Freedom Drive
Freedom Drive is JeepJeep
Jeep is an automobile marque of Chrysler . The first Willys Jeeps were produced in 1941 with the first civilian models in 1945, making it the oldest off-road vehicle and sport utility vehicle brand. It inspired a number of other light utility vehicles, such as the Land Rover which is the second...
's four wheel drive
Four Wheel Drive
The Four Wheel Drive Auto Company, more often known as Four Wheel Drive or just FWD, was founded in 1909 in Clintonville, Wisconsin, as the Badger Four-Wheel Drive Auto Company by Otto Zachow and William Besserdich.-History:...
system used in its compact crossover SUV
Crossover SUV
A crossover SUV is a vehicle built on a car platform and combining, in highly variable degrees, features of a sport utility vehicle with features from a passenger vehicle, especially those of a station wagon or hatchback.Using the unibody construction typical of passenger vehicles, the crossover...
s based on a front wheel drive platform, the Compass
Jeep Compass
The Jeep Compass is a compact crossover SUV introduced for the 2007 model year. The Jeep Compass, along with the Patriot both slot below the Jeep Wrangler as Jeep's entry-level sport utility vehicles, and is one of Jeep's first crossover SUVs....
and Patriot
Jeep Patriot
The Jeep Patriot is a compact crossover SUV introduced in early 2007 for the 2007 model year by the Jeep marque of Chrysler. It debuted publicly in April 2006 at the New York Auto Show and slots between the Compass and Liberty in the Jeep lineup...
. There are two versions of the basic Freedom Drive system for the US Market, called I and II.
Freedom Drive I
Freedom Drive I is a light duty full-time electronically controlled all wheel drive system with a locking mode to set the front/rear torque split for especially slippery conditions in the Jeeps derived from the Chrysler/Mitsubishi GS Platform.Mitsubishi GS platform
The GS platform is a compact car platform co-developed by Mitsubishi Motors and DaimlerChrysler, which underpins the companies' compact cars. After DaimlerChrysler and Mitsubishi went their separate ways in 2004, DaimlerChrysler made substantial changes to the platform...
Applications:
- 2007- Jeep CompassJeep CompassThe Jeep Compass is a compact crossover SUV introduced for the 2007 model year. The Jeep Compass, along with the Patriot both slot below the Jeep Wrangler as Jeep's entry-level sport utility vehicles, and is one of Jeep's first crossover SUVs....
- 2007- Jeep PatriotJeep PatriotThe Jeep Patriot is a compact crossover SUV introduced in early 2007 for the 2007 model year by the Jeep marque of Chrysler. It debuted publicly in April 2006 at the New York Auto Show and slots between the Compass and Liberty in the Jeep lineup...
Freedom Drive II
Freedom Drive II uses the same hardware as the FDI system but adds a continuously variable transmissionContinuously variable transmission
A continuously variable transmission is a transmission that can change steplessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios...
to simulate the benefits of a 19:1 low-range transfer case for off-road use. This function is an alternate program in the CVT and is not a transfer case function. FDII also adds hill descent control system
Hill Descent Control system
Four-wheel-drive and All Wheel Drive vehicles such as the Australian made Ford Territory may have a Hill Descent Control system installed, using the ABS braking to control the car's motion downhill, initially developed by Bosch for Land Rover...
, off-road tuned traction control
Traction control system
A traction control system , also known as anti-slip regulation , is typically a secondary function of the anti-lock braking system on production motor vehicles, designed to prevent loss of traction of driven road wheels...
, and electronic stability program. The Patriot with FDII also feature longer suspension travel, skid plates, tow hooks, and a full-size spare tire. This enables the FDII-equipped Patriot to wear the "Trail Rated" badge from Jeep. Trail Rated Jeep vehicles are determined by meeting several requirements of off-road conditions including water fording, articulation, and other tests.
Applications:
- 2007- Jeep PatriotJeep PatriotThe Jeep Patriot is a compact crossover SUV introduced in early 2007 for the 2007 model year by the Jeep marque of Chrysler. It debuted publicly in April 2006 at the New York Auto Show and slots between the Compass and Liberty in the Jeep lineup...
For the European Market there is a single version which combines elements of both U.S. versions. The European version is available with either a CVT gearbox or most commonly with a 6-speed manual gearbox and has two settings on the traction control and electronic stability program systems to cater for off-road activity, U.S. FDII suspension travel and a full-size spare tire. Skid plates and tow hooks are options in the EU, but the hill descent control system is not available.
Applications:
- 2007- Jeep CompassJeep CompassThe Jeep Compass is a compact crossover SUV introduced for the 2007 model year. The Jeep Compass, along with the Patriot both slot below the Jeep Wrangler as Jeep's entry-level sport utility vehicles, and is one of Jeep's first crossover SUVs....
- 2007- Jeep PatriotJeep PatriotThe Jeep Patriot is a compact crossover SUV introduced in early 2007 for the 2007 model year by the Jeep marque of Chrysler. It debuted publicly in April 2006 at the New York Auto Show and slots between the Compass and Liberty in the Jeep lineup...