Jeep Cherokee (XJ) Stock Specifications

[cher96]

Jeep Cherokee (XJ) Stock Specifications
Author: ThePhantum

All XJs were built as a "Unibody"…meaning that the body and frame rails not just tied together, they are one piece, as opposed to a frame with the body mounted to it (like Wranglers are). All XJ's have solid axles in the front and in the rear. The suspension consists of coil springs up front and leaf springs in the rear. All XJ's came with disc brakes in the front and drums in the rear.

Dimensions
(There may be small differences, dependent upon trim level and/or optional equipment)

Wheelbase = 101.4"
Overall length = 165.3" - 168.8"
Overall width = 67.9" - 70.5"
Track = 58"
Height = 64" (with roof rack 66.8")
Ground clearance from differentials = 7.3" (Upcountry = 8.3")
Approach angle = 37.6º - 38º
Departure angle = 31º - 32.1º
Breakover angle = 21º - 21.9º
Curb weight 2wd = 2,891 lbs - 2,993 lbs
Curb weight 4wd = 3,057 lbs - 3,386 lbs
Cargo capacity = 71.0 cu ft.

Body
The body comes in both 2-door and 4-door styles with a rear hatch (liftgate).

In 94 side-impact beams were added to the doors and roof was strengthened. The 3rd brakelight was added to the top of the liftgate as well.

In 96 the body structure was strengthened some...it was not noticeable in overall appearance.

In 97 the body and interior were redesigned. Most noticeably it gave the body smoother lines by changing the bumpers, flares, and moldings. The front fender was trimmed just below the headlights and replaced with plastic bumper endcaps that wrap around to the wheel well. The windshield washer bottle was relocated to the inside of the drivers side front fender and the liftgate was also changed from fiberglass to sheet metal.

Engines
2.5L I4 carburated - 105 hp @ 5000 rpm, 132 ft lb torque @ 2800 rpm - used in 84-85 models

2.5L I4 TBI (fuel injected) - 117 hp @ 5000 rpm, 135 ftlb @ 3500 rpm - used in 86 and updated in 87-90 to 121hp

2.5L I4 MPI (multi-port injection) - 130 hp @ 5250 rpm, 139 ft lb @ 3250 rpm - used in 91-00

GM 2.8L V6 - 115 hp @ 4800 rpm, 145 ft lb @ 2400 rpm - used in 84-86

Renault 2.1L 4cyl. Turbo Diesel - 85 hp @ 3750 rpm, 132 ft lb @ 2750 rpm - used in 85-87

Italian VM 2.5L Turbo Diesel - 140 hp, 236 ft lb torque - used in overseas XJs

4.0L I6 EFI "Power Tech" - 177 hp @ 4750 rpm, 220 ft lb @ 4000 rpm - used 87-90

4.0L I6 MPI "Power Tech HO" (High Output) - 190 hp @ 4750 rpm, 220 ft lb @ 4,000 rpm - used in 91-95 and updated in 96-01 to 225 ft lb torque @ 3000 rpm (00-01 models use a distributorless ignition system)

Transmissions
Manual Transmissions

AX4 - 4 speed manual - manufactured by Aisin - used 84-86 with 2.5L I4 and 2.8L V6 engines
T4 & T5 - 4 & 5 speed manual - manufactured by Borg Warner - used 84-86 with 2.5L I4 and 2.8L V6 engines
BA10/5 - 5 speed manual - manufactured by Peugot - used only up to 89
AX5 - 5 speed manual - manufactured by Aisin - used with 2.8L V6 and 87+ with 2.5L I4
AX15 - 5 speed manual - manufactured by Aisin - used with 4.0L I6 engines
NV3550 - 5 speed manual - manufactured by New Venture - used in 00-01 in SE models with 4.0L I6 engines

Automatic Transmissions

Torqueflight 904 - 3 speed automatic - used 84-86 with 2.8L V6 and 2.5L I4 engines
30RH - 3 speed automatic - used with 2.5L I4 engine 94?-00
AW4 - 4 speed automatic, electronically controlled - manufactured by Aisin - used from 87-01 (87-91 models include a Power/Comfort button that adjusts the shift points)

Transfer Cases
All the transfer cases used are all chain driven with aluminum housings. T-cases were designated either NP or NV. They are essentially the same t-case...just a different "brand name" (NP was used for the purposes of this list:

NP ="New Process"
NV = "New Venture"

NP207 - "Command-Trac" part-time only - 2.61:1 ratio low range - used 84-87

NP231 - "Command-Trac" part-time only - 2.72:1 ratio low range - shift pattern 2H - 4H - N - 4L - used 87-01

NP228/NP229 - "Selec-Trac" - 4Hi(full-time) - N - 4Lo (part-time) - used 84-87

NP242 - "Selec-Trac" part-time OR full-time - 2.72:1 ratio low range - shift pattern 2wd - 4part-time - 4full-time - N - 4LO - used 87-01

Driveshafts
Front Driveshaft - On 84-87 XJs (NP207 t-case) the front shaft is a "GKN" style shaft. On 87-01 XJs (NP231/242 t-case) the front is a "double cardan" two-piece driveshaft with a CV joint at the transfer case end.

Rear Driveshaft - The rear is a one-piece shaft with standard u-joints at both ends. The slip yoke is located on the output shaft of the transfer case. On 84-95 models, the yoke slides in and out of the transfer case and is lubricated by the ATF fluid internally. On 96-01 due to a design change, the slip yoke is external (does not slide in and out of the transfer case). This slip yoke is covered with a rubber boot.

Axles
Front Axles

Dana 30 high pinion - reverse cut - 27 spline, 1.16" diameter shafts, 7.13" ring gear - used 84-99 (some axles through 91 are vacuum disconnect, 92+ are non-disconnect, 89-95 with ABS have 5-297x u-joints, all 95+ have 5-297x u-joints, all others have 5-260x u-joints)

Dana 30 low pinion - standard cut - 27 spline, 1.16" diameter shafts, 7.13" ring gear, 5-297x u-joints - used 00-01

Rear Axles

Dana 35 non c-clip - 27 spline, 1.18" diameter shafts, 7.58" ring gear, 2.62" axle tube - used 84-89

Dana 35 c-clip - 27 spline, 1.18" diameter shafts, 7.58" ring gear, 2.62" axle tube - used 90-01

Chrysler 8.25 - 27 spline, 1.17" diameter shafts, 8.25" ring gear, 3" axle tube - used 91-96

Chrysler 8.25 - 29 spline, 1.21" diameter shafts, 8.25" ring gear, 3" axle tube - used 97-01

Dana 44 non c-clip - 30 spline, 1.31" diameter shafts, 8.5" ring gear, 2.75" axle tube - used 87-89 on some (not all) XJs equipped with towing package.

Note: Dana 35 axles sometimes referred to as Dana 35C - The "C" does not stand for c-clip. It stands for "custom" meaning it came from Dana unfinished.

Note: 8.25 axles - none of these axles were used on XJ's with ABS brakes. If you have ABS, you have the Dana 35. Without ABS you could have either axle. 8.25 axles are c-clip.

Gearing
3.07 - used with 4.0L engine / manual transmission
3.31 - only available on older (pre87?) 2 door XJs with "Fuel Economy" package
3.55 - used with 4.0L engine / automatic transmission
3.73 - found in some XJs with the towing package
4.10 - used with 2.5L engine usually, and older XJs with the "Off-Highway Vehicle" package.

Cooling Systems
Open style - any normal cooling system used today. Opposite of closed style described below.

Closed style - has no radiator cap and utilizes a pressure bottle. This style cooling system was used in 87-90 XJs.

Airbags
Drivers side airbag (mechanical) was added in 1995.
Passenger side airbag was added in 1997. Airbags changed from mechanical to electronic in this year also.
Production Numbers
Number of XJ's built in given year:

1984 - 93,326
1985 - 120,328
1986 - 107,225
1987 - 139,295
1988 - 187,136
1989 - 207,216
1990 - 151,230
1991 - 151,578
1992 - 137,826
1993 - 144,961
1994 - 123,391
1995 - 120,234
1996 - 286,463
1997 - 258,958
1998 - 182,845
1999 - 186,116
2000 - 165,590
2001 - 120,454

Total = 2,884,172

Trim Levels
84 - Base, Wagoneer, Pioneer, Chief
85 - Base, Wagoneer, Pioneer, Chief, Laredo
86 - Base, Wagoneer, Pioneer, Chief, Laredo
87 - Base, Wagoneer, Pioneer, Chief, Laredo, Limited
88 - Base, Wagoneer, Pioneer, Chief, Laredo, Limited, Sport
89 - Base, Wagoneer, Pioneer, Chief, Laredo, Limited, Sport
90 - Base, Wagoneer, Pioneer, Chief, Laredo, Limited, Sport
91 - Base, Briarwood, Chief, Laredo, Limited, Sport
92 - Base, Briarwood, Chief, Laredo, Limited, Sport
93 - Base, Sport, Country
94 - SE, Sport, Country
95 - SE, Sport, Country
96 - SE, Sport, Country, Classic
97 - SE, Sport, Country
98 - SE, Sport, Classic, Limited
99 - SE, Sport, Classic, Limited
00 - SE, Sport, Classic, Limited, Freedom
01 - Sport, Limited, 60th Anniversary Edition


Citation: http://jeephorizons.com/tech/xjstockspecs.html

[cherok]

Hellelua and amen!

[cher96]

In the last part of 1996, Jeep ran out of 27 Spline C8.25 Axles. They then installed the 29 Spline into the C8.25 Axle Assembly. There is a Tag on the backside of the C8.25 Differential. This Tag may lead one to find out which Axles they have. I do not know for sure since mine has broken off.

If you can not find the Axle Spine used, then unfortunately, you will have to count the Splines on the Axle. Yes, that means taking it apart.

The Jeep Build Sheet will not have this information on it. I know because my XJ was made late in that model year and I do not have my tag and I have tried every way I could without having to take it apart.

While off roading, I blew a U-Joint and my drive shaft smashed a huge hole in my NP231. While changing my NP231 with a '94 Transfer Case I noticed mine was different. My XJ had a '97+ Model NP231. I researched it and found out that they ran out of NP231s that year too. So, I guess there is a high chance I have the 29 Splined C8.25

[Melissa]

I have that spec sheet right next to me and I look at it often

[cher96]

2.5L I-4

The AMC (American Motors Corporation) straight-4 engine is used by a number of AMC, Jeep and Dodge vehicles from 1984 through 2002.

2.5L Straight-4

The 2.5L inline-4 is a shortened version of the 4.2L 258 I-6 engine bored to 3.88 in (99 mm) and de-stroked to 3.19 in (81 mm). The block is basically the same as the 4.2L I-6 with a larger bore and the two center cylinders removed. The head featured a new combustion chamber and port design which was later used on the 4.0L I-6 -- the 2.5L I-4 head is stretched by two cylinders in the center.

Instead of the standard AMC bell housing bolt pattern, AMC/Jeep engineers adopted the General Motors small V6 and four cylinder bolt pattern (commonly used with GM's transverse-mounted powerplants) for their new engine, because the 2.5 replaced four-cylinder engines which had been purchased from GM; and because AMC continued to buy the 2.8L V6 from GM until the 4.0L I-6 was introduced in 1987. The four-cylinder and V6 shared the same drivetrain components, whereas stronger transmissions were needed for the 4.0L I-6.

The AMC I-4 appeared in 1984 with the new XJ Cherokee and was produced through 2002 for the Jeep Wrangler and Dodge Dakota pickup, which used the AMC/Jeep designed four since 1996.

Specifications
Firing order
Enlarge
Firing order
Bore x Stroke 3.88" x 3.19"
Displacement 150ci (2.5L)
Horsepower Output (final year) 123 HP SAE (89 kW) @ 5,400 rpm
Torque Output (final year) 145 ft lbs (197 N·m) @ 3,250 rpm
Valvetrain Eight overhead valves
Main bearings Five
Compression ratio 9.1:1 to 9.2:1 depending on year
Firing Order 1-3-4-2 Clockwise

2.5L I-4

The AMC (American Motors Corporation) straight-4 engine is used by a number of AMC, Jeep and Dodge vehicles from 1984 through 2002.

2.5L Straight-4

The 2.5L inline-4 is a shortened version of the 4.2L 258 I-6 engine bored to 3.88 in (99 mm) and de-stroked to 3.19 in (81 mm). The block is basically the same as the 4.2L I-6 with a larger bore and the two center cylinders removed. The head featured a new combustion chamber and port design which was later used on the 4.0L I-6 -- the 2.5L I-4 head is stretched by two cylinders in the center.

Instead of the standard AMC bell housing bolt pattern, AMC/Jeep engineers adopted the General Motors small V6 and four cylinder bolt pattern (commonly used with GM's transverse-mounted powerplants) for their new engine, because the 2.5 replaced four-cylinder engines which had been purchased from GM; and because AMC continued to buy the 2.8L V6 from GM until the 4.0L I-6 was introduced in 1987. The four-cylinder and V6 shared the same drivetrain components, whereas stronger transmissions were needed for the 4.0L I-6.

The AMC I-4 appeared in 1984 with the new XJ Cherokee and was produced through 2002 for the Jeep Wrangler and Dodge Dakota pickup, which used the AMC/Jeep designed four since 1996.

Specifications

Bore x Stroke 3.88" x 3.19"
Displacement 150ci (2.5L)
Horsepower Output (final year) 123 HP SAE (89 kW) @ 5,400 rpm
Torque Output (final year) 145 ft lbs (197 N·m) @ 3,250 rpm
Valvetrain Eight overhead valves
Main bearings Five
Compression ratio 9.1:1 to 9.2:1 depending on year
Firing Order 1-3-4-2 Clockwise

Notes

The final production year used sequential mulitple-port fuel injection. For comparison, the 4.2L I-6 produced 112 HP @ 3,200 rpm and 210 ft lbs of torque @ 2,000 rpm in its final year with the computer controlled carburetor.

For several years, the engine was detuned for the Wrangler; from at least 1992 to 1995, it produced 130 horsepower and 149 ft lbs of torque with 9.2:1 compression in the Cherokee and Comanche.

2.8L V6

Under powered for the duty

Indeed, if you're looking for power under the hood of a Jeep, look elsewhere. However, with proper tuning and maintenance, the 2.8L V6 can be a servicable powerplant.

The 2.8L is a sixty degree V6 manufactured for Chevrolet as an economy motor. It was installed in Jeep vehicles with a two-barrel Rochester carburetor. (One barrel is a primary while other is a vacuum-actuated secondary.)

Many 2.8L owners have reported improved performance after installing a high-performance air filter, such as those made by K&N. High performance parts, such as camshafts and aluminum, four-barrel intakes are also available. However, owners shouldn't expect significant power gains from such hardware.

The 2.8L V6 can often have trouble passing emissions tests, especially at high altitudes. The state of Colorado emissions control web site recommended installing a PCV valve for the Chevrolet 305 V8 and adjusting the metering rod in the carburetor primary to keep it from lifting prematurely.

4.0L I-6

The 4.0 L (242 in³; 3956 cc) straight-6 was an evolution of the 4.2L 258 I-6 and 2.5L I-4 and appeared in 1987. It had the same 3.88 in (98.4 mm) bore as the 2.5 with a longer 3.41 in (86.7 mm) stroke. The 4.0 was discontinued at the end of the 2006 model year as the redesigned Jeep JK Wrangler uses Chrysler's 3.8L V-6 OHV V6.

The first 4.0 engines in 1987 had RENIX (Renault/Bendix) engine control systems, which were quite advanced for their time, but are now handicapped because there are very few scan tools which can be "plugged in" to a RENIX system for diagnosis. The Renix also used a very advanced engine knocking sensor, which allowed the computer to know if detonation was occurring, thus allowing the computer to make the appropriate changes to prevent this.

The 1987 RENIX 4.0 made 173 hp (129 kW) and 220 lb-ft (298 N·m) of torque. In 1988 the 4.0 received higher flowing fuel injectors, taking output to 177 hp (132 kW) and 224 lb-ft (304 N·m) respectively.


4.0L I-6

The 4.0 L (242 in³; 3956 cc) straight-6 was an evolution of the 4.2L 258 I-6 and 2.5L I-4 and appeared in 1987. It had the same 3.88 in (98.4 mm) bore as the 2.5 with a longer 3.41 in (86.7 mm) stroke. The 4.0 was discontinued at the end of the 2006 model year as the redesigned Jeep JK Wrangler uses Chrysler's 3.8L V-6 OHV V6.

In 1991 Chrysler Corporation, then the owners of the Jeep brand, redesigned the RENIX engine control computer and raised the intake ports approximately 1/8″ for a better entry radius. Chrysler also enlarged the throttle body and redesigned the intake and exhaust manifolds for more efficiency, and the fuel injectors were once again replaced with higher flowing units. The camshaft profile was also changed. The net result of all these changes was an engine that made 190 hp (142 kW) and 235 lb-ft (312 N·m) of torque. Badging on Jeeps equipped with this engine read "4.0 Litre HIGH OUTPUT". The new cam profile combined with altered computer programming eliminated the need for an EGR valve and knock sensor, but make the engine more sensitive to alterations, especially where emissions are concerned.

Small changes were made to the cylinder head for the 1995 model year. In 1996, the engine block was redesigned, and a new strengthened unit was then used. The new block made use of more webbing cast into the block, and a stud girdle for added rigidity of the crankshaft main bearings. The cylinder head was also again changed around 1998 to a lower flowing, but more emissions friendly, design. Engines installed in 1999 Grand Cherokees carried the Power Tech name, which was subsequently passed on to 4.0s in all Jeep models.

The 4.0 engine was in production in North America until 2006, when the Jeep Wrangler TJ was replaced by the new JK design that uses Chrysler's OHV 3.8L V-6. It is foreseeable that this engine may be made for many more years in the People's Republic of China, where a slightly modified version of the XJ Jeep Cherokee with 2.5L I-4 and 4.0 engines are still being produced.

Output as of 2004 was 190 hp (142 kW) at 4600 rpm with 235 lb-ft (312 N·m) of torque at 3200 rpm.

This engine is considered one of the best offroad engines ever made. The extreme low end torque is ideal for trailing and rock crawling. The only downfall to the engine is the low power output for mudding applications but this can be fixed with various aftermarket options including a supercharger for the engine. Interchangeability within the late AMC/Jeep engine family is superb. The better flowing 4.0 L heads can easily be modified to fit earlier engines right along with the fuel injection system. The longer stroke 258 crankshaft and rods will drop right in the slightly larger bore 4.0 L block, easily creating an even higher torque 4.5 L engine with the stock bore (4.6 L bored 0.030″ over, and 4.7 L with a 0.060″ overbore). Blocks should be sonic checked for adequate cylinder wall thickness before boring 0.060″ over.

Citation: http://jeephorizons.com/tech

[cher96]

Aisin Warner AW4 Four-Speed Overdrive Automatic Transmission

From Novak Conversions, Knowledge Base

* The Aisin Warner AW4 transmission is a four-speed overdrive automatic transmission used in the 1987-2001 Jeep XJ Cherokee and MJ Comanche models with the AMC 4.0L (242 cid) in-line six cylinder engine.
* Its only year in the ZJ Grand Cherokee was 1993, and only with the AMC 4.0L engine.

* A similar transmission is used in some Toyota 4WD applications, known as the A340F or A340H depending on the transfer case.
* It is also used in some Toyota 2WD / RWD applications, known as the A340E.
* Another user is Isuzu, which uses this tranmission with their V6 engine.

The AW4 is a light to medium-duty transmission. Ours, our callers' and customers' experiences with the AW4 are less than stellar. They have a tendency to generate excessive amounts of heat, and are known for unnecessarily consuming more engine power than some other automatics. The shift points in the AW4 feel odd, and the spotty engagment of the lockup torque converter is idiosyncratic.

Gear Ratios for the AW4 are 2.80, 1.53, 1.00 & .75.


Identification

* The AW4 has a removable bellhousing.
* The case is smaller in diameter than most automatics, and features cast-in ribbing down the rear half of the case.
* The bell housing for the AMC 4.0L I6 engine has a port for the crank position sensor.
* The earlier Jeep AW4 has a 21 spline output shaft for connecting to the transfer case input shaft.
* With the release of the HO 4.0L in the 1991 the AW4 was upgraded to a 23 spline output shaft.
* The AW4 may be identified as model #40-30LE for 4wd versions. and as model #30-43LE for 2wd versions.


Transfer Case CompatibilityThe Jeep AW4 was factory-married to the Jeep New Process (aka New Venture) Model 231 transfer case, in addition to the NP242 Full-Time transfer case.


Engine Compatibility

* AMC / Mopar Jeep - As the AW4 was married to the Jeep 4.0L in-line six cylinder engine, it is OEM compatible with them.
* By using the Isuzu bell housing, the AW4 can be bolted to the GM 60degV6 (2.8L/3.1L/3.4L) engines and others using that bell housing bolt pattern, such as the FWD Buick 3800 V6, and the early 1990s Cadillac 4.9L (pushrod) V8 engine, among others.
* There are no known bell housings to bolt this transmission to the small block Chevy V8 / 4.3L Chevy V6, nor the Ford 5.0L V8.

* The AW4 is an electronically controlled transmission, and receives commands from a remote mounted electronic module.
* On Jeeps 1996 and earlier equiped with this transmission the Transmission Control Module (TCM) was an independent unit.
* On later Jeeps the transmission controls are integrated into the engine / power train control module.
* It appears that third party vendors can supply stand alone controllers for the Jeep AW4 / Toyota A340 transmissions.

Citation: http://www.jeepforum.com/wiki/index.php/AW4

[cher96]

AX-15

Overview

The AX-15 is a medium duty five speed transmission with an aluminum case. It is manufactured by Aisin in Japan and, although they are not compatible, the same model transmission is used in some Toyota trucks. In 1994 the clutch slave cylinder was moved to the outside of the bellhousing, so these AX-15s have a different input bearing retainer to accommodate the different throwout bearing. The input shaft is also slightly different, so a different pilot bushing is used. All AX-15s have a 1 1/8" 10 spline input shaft and a 23 spine output shaft. The AX-15 was first used in the XJ Cherokee and MJ Comanche with the 4.0L I-6 engine. In mid 1989, the AX-15 was used in the YJ Wrangler with the 4.2L 258 I-6 engine and it continued to be used with the 4.0L engine. The first year of the ZJ Grand Cherokee, the AX-15 was rare option only with the 4.0L engine.

Tech Info
Aisin AX15 Gear Ratios First Gear 3.83
Second Gear 2.33
Third Gear 1.44
Fourth Gear 1.00
Fifth Gear 0.79
Reverse 4.22

Citation: http://jeephorizons.com/tech

[cher96]

NV / NP 231

A medium Duty part-time transfer case, the np231 features shift on-the-fly 4hi, a good lo range, and massive aftermarket support. Cast in aluminum, the case should have a tag on the back saying New Process Gear (or New Venture Gear), Model 231. New versions of the NP231 are referred to as NVG231 or NV231 which stands for New Venture Gear. The tag on the back of the transfer case will reflect the name change. Only the name is different. A NV231 HD model is used in some ZJs. Presumably this is a "heavy duty" version for Jeeps with the big V8s, which features a wider chain and corresponding sprockets etc.

There are versions of this chain driven transfer case that take 21 and 23 spline input shafts. The 23 spline version is used behind the AX-15 and NV3550. The 21 spline is used behind the AX-5 and the BA-10/5. The output for the front driveshaft is on the drivers side. Low range is 2.72 and high is 1.00.

Tech tips

If you own a 21 spline NP231 and you want to swap in a 23 spline transmission, you can either look for a cheap 23 spline NP231 at the junk yard or go to your local Jeep Parts Dealer and order up a new input shaft part #5300-6085. This is the part you need to convert your NP231 to 23 spline input.

Model number explanation

Sankar K. Mohan of New Venture Gear defined what the numbers on their T-cases mean:

The first number is the number of speeds:

* "1" = one speed (high range). Example – the NV 136.
* "2" = two speeds (high range and low range). Example – the NV 231.

The second number is the strength:

* The NV 231 is designated "3" in strength, not as heavy duty as their largest T-cases, which go up to a "7" (eg, NV 273, for vehicles with a GVW of 17,500 lb).

The third number designates the type of T-case:

* "1" = part-time 4WD
* "2" = full-time 4WD with an open center differential plus lockable part-time option – like the Selec-Trac NV 242 of the Jeep Cherokee and Dodge Durango, or the Hummer’s NV 242HD AMG.
* "3" = electrically shifted.
* "4" = not currently used.
* "5" = Torsen-type differential.
* "6" = computer controlled multi-plate wet clutch, like GM’s AutoTrac NV 246.
* "7" = GeroDisc – like the Grand Cherokee’s Quadra-Trac II NV 247.
* "8" = not currently used.
* "9" = viscous coupling.


Usage

Since 1988, the NP231 has been the "Command Trac" transfer case used in the XJ Cherokee, MJ Comanche, and YJ Wrangler. It has been the "Command Trac" transfer case in the ZJ Grand Cherokee since its introduction. The new TJ Wrangler continues to use the NP231, but the NP231 used in the TJ has a different tail housing that allows the removal of the drive shaft with out losing transfer case fluid.

Both versions of the NP231 used in the Wranglers have an over all length that is long for a short wheel base vehicle. This can cause driveline vibration and premature u-joint failure especially for a lifted vehicle. There are kits to convert the tail housing to a standard yoke to allow the use of a longer rear drive shaft. The kit is called a SYE (slip yoke eliminator), it is recommended to get one when going with more than 4" of lift on the wrangler models (although in some cases modifications are needed in as little as 2" of lift, but in that small of a lift you can get by with a transfercase drop). The SYE kit is available as a standard fixed yoke or a super short shaft kit. Short shaft kits cost a bit more but allow you to run a longer driveshaft to decrease driveline vibes, and therefore allowing you to have more lift. There is also a 4:1 low range reduction and a "2 lo" (allows you to drive in 2wd but in your low range setting) kit for the NP231. Wranglers are only available with "Command Trac", so the NP231 or NP207 (the NP241 in rubicons)are the only transfer cases available from the factory in any Wrangler model.

Operation

Using the 231 is straight forward. During normal operation on road the shifter will be in the 2-hi possition. The operator may shift into 4-hi while driving if the situation requires more traction. Shifting into 4-lo may only be done once the vehicle is stopped or moving slowly and the clutch is engaged. While in 4-lo, vehicle speed must not exceed 40 MPH. When shifting back to 4-hi or 2-hi from 4-lo the vehicle must be stopped or moving slowly and the clutch is engaged.


Source: http://jeep.off-road.com/jeep/article/articleDetail.jsp?id=260351

Technical Info
NV 231 Specs Hi-Range Ratio 1:1
Lo-Range Ratio 2.72:1
Drive Type Chain
Case Material Cast Aluminum
Shift pattern 2-hi | 4-hi | N | 4-lo
Shift on the fly Yes (4-hi up to ~45mph)
Dry weight ~75 lbs
Oil capacity 2 Quarts
Rated GVW Please contribute here
Input shaft spline count 21 & 23

[cher96]

NP242 Selec Trac

Offered in XJ Cherokee, ZJ Grand Cherokee, WJ Grand Cherokee and KJ Liberty. Shift pattern: 2WD - 4 PARTTIME - 4 FULLTIME - N - 4 LO. It is an aluminum case with chain drive and can use a center differential for its front/rear power split or lock the shafts together depending on mode. Uses Dexron III ATF fluid.

It has a 2.72:1 low range and offers 2WD, 4WD Part-time, 4WD Full-time, Neutral & 4WD Low. The 2WD and 4WD Full Time options may be used on any road surface including dry pavement. The 4WD Part Time and 4WD Low may only be used on slick, low traction surfaces such as snow, sand, dirt, gravel and such. It is an "on the fly" transfer case allowing shifts between 2WD, Fulltime 4WD and Parttime 4WD at speed up to 55 MPH. 4WD Lo is handled differently, see below.


Selec-Trac Features:

* Either 2 or full-time 4-wheel drive in HI range;
* A N (Neutral) position to disengage the axles from the powertrain
* Part time four-wheel drive in Hi or Lo range.

Select either 2-wheel drive (2WD), full time 4-wheel drive (4 FULLTIME) or part time 4 wheel drive (4 PARTTIME) by moving the shift lever to desired mode. Mode selection can be made *WHILE THE VEHICLE IS MOVING AT ANY SPEED UP TO 55 MPH.*


NOTE: If shift lever is moved from one position to another
while the vehicle is not moving, it may be necessary to move
the vehicle forward or backwards slightly for the transfer case
to fully engage 4WD, especially in cold weather.

NOTE: it may be necessary when shifting on the fly between 2WD,
4 PARTTIME or 4 FULLTIME to briefly lift off the throttle once or
twice, especially in cold weather.

CAUTION: Never attempt to engage 4WD LO when vehicle is moving faster
than 2-3 mph (3-5 kmh). Transfer case damage may result.

*WARNING* you can't switch to 4WD LO "on the fly" like you can with
4WD HI.The vehicle must be moving slowly (2-3 mph) and the
*TRANSMISSION* must be shifted to neutral.

*WARNING: NEVER PARK YOUR VEHICLE WITH RANGE LEVER IN THE
N (NEUTRAL) POSITION. THE VEHICLE COULD ROLL UNEXPECTEDLY
EVEN IF AN AUTOMATIC TRANSMISSION IS PLACED IN PARK OR A
MANUAL TRANSMISSION IS IN GEAR.*


Modes

* 2WD or 4WD Full Time (2WD or 4 FULLTIME) - In either position, the vehicle may be operated on all road surfaces. In 4WD Full Time, Select Trac offers better traction when roads are wet, snow covered or icy. Use Selec-Trac 4WD Fulltime year-round (full time) if you wish. Comparable to what other vehicles call "all wheel drive."

* N Position (Neutral)- In this position the axles are disengaged from the powertrain. The vehicle may be towed without removing the propeller shafts. Place an automatic transmission in Park or a manual transmission in gear after the N position is engaged.

* 4WD Part Time High Position (4 PARTTIME) - This position provides 4WD for occasional use in low traction driving conditions such as snow, dirt etc. NOT FOR USE ON DRY PAVEMENT as transfer case damage may result.

* 4WD Lo Position (4 LO) - This position provides 4WD for occasional use when *OFF-ROAD* driving conditions require low speed pulling power. NOT FOR USE ON DRY PAVEMENT as transfer case damage may result.


WARNINGS / CAUTIONS

CAUTION: Never attempt to engage 4WD LO when vehicle is moving faster
than 2-3 mph (3-5 kmh). Transfer case damage may result.

*WARNING* you can't switch to 4WD LO "on the fly" like you can with
4WD HI. The vehicle must be moving slowly (2-3 mph) and the
*TRANSMISSION* must be shifted to neutral.

*WARNING: DO NOT DRIVE THE VEHICLE UNLESS THE TRANSFER CASE
IS FULLY ENGAGED. FAILURE TO COMPLETELY ENGAGE A POSITION
CAN CAUSE TRANSFER CASE DAMAGE OR LOSS OF POWER AND VEHICLE
CONTROL. BE SURE YOU KNOW THE SHIFT PATTERN OF YOUR VEHICLE.*

WARNING: DO NOT INSTALL SELECTIVE DRIVE HUBS ON SELEC-TRAC
VEHICLES. IF THESE HUBS ARE LEFT UNLOCKED WHEN THE VEHICLE
IS PARKED, THE VEHICLE COULD ROLL UNEXPECTEDLY--EVEN IF AN
AUTOMATIC TRANSMISSION IS IN PARK OR A MANUAL TRANSMISSION
IS IN GEAR.*

Citation: http://www.jeepforum.com/wiki/index.php/NP242

[sinat]

what gear oil does a Cherokee use? or does it vary by model?

[4.3LXJ]

ATF in the tcase and 80W90 in the differentials

[NotSmall]

Well, my rear end looks like a chrysler 8.25 and has ABS. Possible? Vehicle has a police package.

[Mudderoy]

Well, my rear end looks like a chrysler 8.25 and has ABS. Possible? Vehicle has a police package.

I guess anything is possible, but I've always read that ABS in a XJ = Dana 35

[NotSmall]

Well Mudderoy, You were correct, I have a Dana 35c rear end ... upon checking further. Thanks

[bluedragon436]

I would def think that would be a way to ruin the 8.25 if it did have ABS.. but wouldn't be a surprise to me, honestly!!

[Mudderoy]

Well Mudderoy, You were correct, I have a Dana 35c rear end ... upon checking further. Thanks

Well if you are bummed don't be. Easy and cheap to upgrade to a Chrysler 8.25. :D

[4xfishfinder]

Anyone know the stock backspace of the wheels on a 94 HP 30?

[bigjim350]

Should be 5"

Sent from my nerdy smartphone

[sinat]

dumb question, how can you tell what tranny/ transfer case you have?

[4.3LXJ]

Transmission will be an AW4 if auto and AS15 if standard. Transfer case has a small round tag on it in the center of the back side with the low gear ratio of 272 and the number of the case stamped in it

[sinat]

ok, thank ya,