[Bain98xj]

What are the disadvantages and advantages of the 2 transfercases? and i have the 231 now but have a friend that has a 242 in his xj that he wrecked and told me i can take the tcase if i want before he starts parting it out. so would i be able to pull the 231 and put the 242 in without any major mods?

[xjfever]

The 231 is a stronger more reliable t-case, but if you do a lot of driving on icy snowy roads the 242 can be used in fulltime 4x4 without having to go from 2wd to 4wd as the conditions change. The 231 can not be driven in 4wd on pavement when traction is good. The swap will require a small amount of wiring to make the fulltime light work, but it is mostly a bolt in swap.

[mortalenema]

I've never had a reliability issue with a 242. I admit the 231 is marginally stronger. The real advantage to the 231 is aftermarket support. You can build a 231 stronger and SYE it more cheaply than a 242. If you live somewhere where the roads are an icy mix much of the year, the 242 is great. I have never had u-joints disintegrate on the 242 equipped Jeeps I've driven over the years. All my 231 equipped Jeeps have had u-joint issues. And, yes, I used 4wd correctly. I always shifted out when not needed. It's just that you can't always pull out of 4wd in time to stop a little binding/wear and tear. I blame Minnesota. The road surface is always the opposite of what selection you have on your TC.

[GeologistFelix]

Hack-and-tap SYEs are actually the same price for both t-cases...because it's the same kit. The only difference is that the NP242 is slightly longer, so you need a slightly shorter rear driveshaft. So, expect $200-250 for the kit, $15 for a junkyard XJ front CV driveshaft, and maybe $50 to get a driveshaft shop to shorten and rebalance the XJ shaft.

[leftlanetruckin]

Originally Posted by GeologistFelix

Hack-and-tap SYEs are actually the same price for both t-cases...because it's the same kit. The only difference is that the NP242 is slightly longer, so you need a slightly shorter rear driveshaft. So, expect $200-250 for the kit, $15 for a junkyard XJ front CV driveshaft, and maybe $50 to get a driveshaft shop to shorten and rebalance the XJ shaft.

Although that does not give you the stronger main shaft of a true 231 SYE kit does it?

Martin

[lowicz96]

I do miss my 96 with a np242 just for the full time 4x4. Its nice in winter when the roads are crappy, just put it in full time and you dont have to worry about it as much as the 231

[Vassago]

what ive found on the NP242 what i have on my xj and love
Type 3: NV242 Selec-Trac®

• Type: Full-time
• Full time 4WD operation sends power to both the front and rear axles under normal driving conditions.
• Open center differential enables four-wheel drive operation on any road surface.
• Shift-on-the-fly capability allows switching between two-wheel drive, part-time high range 4WD and full-time 4WD, at speeds up to 55 mph
• Available Trac-Lok limited-slip rear differential with torque-sensing device for maintaining traction on slippery surfaces. Automatically distributes torque to the rear wheel with the most traction, thereby reducing wheel spin at the other wheel

The NV242 provides full time 2-wheel, or 4-wheel drive operation. A differential in the transfer case is used to control torque transfer to the front and rear axles. A low range gear provides increased low speed torque capability for off road operation. The low range provides a 2.72:1 reduction ratio

The 2WD and 4x4 full time ranges can be used at any time and on any road surface. The 4x4 part-time and 4 Lo ranges are for off road use only. The only time these ranges can be used on hard surface roads, is when the surface is covered with snow and ice.
The geartrain is mounted in two aluminum case halves attached with bolts. The mainshaft front and rear bearings are mounted in aluminum retainer housings bolted to the case halves. Two versions of the NV242 are used in the WJ vehicles, NV242LD and NV242HD. The two transfer cases can be distinguished from one another by the rear output shaft retainer. The NV242LD uses a rubber boot to cover the rear output shaft, while the NV242HD uses a cast aluminum housing.
Operating Modes:
2WD (Sends all power to rear wheels)
4WD High, full-time (Sends power to all wheels)
4WD High, part-time (Locks both front and rear driveshafts for increased traction)
NEUTRAL (Allows vehicle to be towed)
4WD Low, part-time (Doubles the transfer case gear ration for severe road conditions and low-speed pulling power)

Low Range Reduction Ratio: 2.72:1
Center Differential: Open, Planetary with low-range lock
Torque Split: F/R 48/52
Maximum Capacity Torque: 1486 lbs.-ft.
Weight: 86 Lbs.
Oil Fill Capacity: 2.85 pts.
A circular ID tag is attached to the rear case of each transfer case. The ID tag provides the transfer case model number, assembly number, serial number, and low range ratio. The transfer case serial number also represents the date of build.

[Vassago]

Originally Posted by leftlanetruckin

Although that does not give you the stronger main shaft of a true 231 SYE kit does it?

Martin

that's because the aftermarket support isn't there. is jeep had made the Np242 TC the standard TC instead of an option, there would be more of a market for a true SYE kit, but they didn't.

[Vassago]

The Novak Guide to the
New Process / New Venture Gear 231 Transfer Case

The Jeep NP 231 transfer case was introduced in the 1988 model year. Jeep's YJ Wrangler and the XJ / MJ Cherokees with the Command Trac option were the first models to feature it. The 231 was initially tagged as the 231AMC, and as ownership of AMC was taken over by Chrysler, it was later designated as the 231J. This transfer case was later to be called the NVG (New Venture Gear) 231J. Despite the different nomenclature, they are essentially the same transfer case, with the bulk of their parts interchanging.
Chain driven transfer cases were first used in the 1970's with partial success - Jeep's Borg Warner QuadraTrac being a notable instance. They increased in reliability and strength in the early to mid-eighties and essentially hit their stride in the late-eighties. The 231 has continued in the trend of chain-driven cases and is one of the most successful and popular of them all.
Features
The 231 has a driver's side front output and centerline rear output. The NP231 features two ranges; a low range gear that is a respectable 2.72-to-1 (the lowest of all the Jeep transfer cases with the exception of the NP241OR) and a direct-drive in high range. It features three modes; two-wheel-drive, four-wheel-drive and neutral - for a factory combination of 2H, 4H, N, 4L. Aftermarket modifications allow for the addition of a 2 Low position.
Early 231s from 1988 through 1991 featured a conventional mechanical (cable) drive speedometer output. In 1992, Jeep introduced a three-wire, digital square wave Vehicle Speed Sensor (VSS), in the vein of modern automotive systems.
This tag indicates a 231J transfer case, with a part number of 52099211, a build date of 6-21-99 and a gear ratio of 2.72:1. The design of the 231 is very good. They were engineered for durability and simplicity of build - both an advantage to the OEM assemblers as well as individuals servicing them. The NP231 transfer case has turned out to surprise us in its strength, gearing, upgradeability and servicability. Most of our customers choose to retain their Jeep 231 with their conversions. It is very common for them to offer good service behind some of the strongest engines and transmissions.
The standard 231 weighs about 70 lbs. HD 231's can weigh up to 80 lbs.
Identification
This transfer case is identified by its red and silver tag on the rear of the case. They are also easily identified by appearance. They feature a six-bolt front face.
There are Chevy & Dodge versions of the 231. The GM versions use a five-bolt front face that is incompatible with the Jeep and Dodge six-bolt styles. The Chevy versions also use long factory adapters and have no support for improvements - particularly in shifter upgrades and tailhousing upgrades like those available for the Jeep versions.
Heavier-duty HD and DHD units are available in ZJ Jeeps and Dodge trucks, respectively. The standard duty OEM 231 transfer cases are capable of transferring from 1600 to 1900 ft. lbs of torque (as claimed by NVG - actual experience puts this number quite a bit higher).
Wide chains, larger planetaries and stronger mainshaft/tailhousing assemblies (see Tailhousings, below) are also available if even more strength is desired. With such upgrades, a transfer case capable of handling 2900+ ft. lbs. of torque is attainable. This is a result of good engineering and refinement.

[Vassago]

The Novak Guide to the
New Process / New Venture Gear 242 Transfer Case

The Jeep NP242 transfer case was introduced in the 1987 model year as a replacement for the NP228. The 242 premiered in the XJ Cherokee / Wagoneer and MJ Commache as the SelecTrac option. It was used in the 1991-1998 ZJ Grand Cherokee. The 242 persisted throughout the full run of XJ Cherokees and continued on in the 2002 KJ Liberty.
The 242 was originally tagged as the 242AMC, and as ownership of AMC was taken over by Chrysler, it was later designated as the 242J. This transfer case was later called the NVG (New Venture Gear) 242. Despite the different nomenclature, very few mechanical changes were required or made throughout their production span.
Earlier attempts at torque-biasing transfer cases were spotty in their success, beginning with the QuadraTrac in the 1970's and continuing with the NP219 and NP228. The 242 has continued in the trend of chain-driven cases and has technically and commercially been more successful than its predecessors.
Features
The 242 has a driver's side front output and centerline rear output. The NP242 features two ranges; a low range gear that is a respectable 2.72-to-1 low and a direct-drive in high range. It features three drive modes; 2wd, full-time 4wd and part-time 4wd, yielding:

• two-wheel-drive, high (direct-drive)
• four-wheel-drive, high (48/52 differential torque-biased-drive)
• four-wheel-drive, high (locked, part-time)
• neutral
• four-wheel-drive, low (locked, reduction-drive)

This tag indicates a 231J transfer case, with a part number of 52098886, a build date of 5-7-96 and a gear ratio of 2.72:1. Though Full-Time is the nomenclature used, this is a position that is used sparingly, as component wear throughout the geartrain and tires is a result, in addition to decreased fuel-efficiency.
Early 242s from 1988 through 1991 featured a conventional mechanical (cable) drive speedometer output. In 1992, Jeep introduced a three-wire, digital square wave Vehicle Speed Sensor (VSS), in the vein of modern automotive systems.
The design of the 242 is fairly good. They were engineered for durability and simplicity of build - both an advantage to the OEM assemblers as well as individuals servicing them. The NP242 transfer case has turned out to be stronger than expected. Most of our customers choose to retain their Jeep 242 with their conversions. It is very common for them to offer good service behind some of the strongest engines and transmissions.
The 242 weighs about 85 lbs.
Identification
This transfer case is identified by its red and silver tag on the rear of the case. They are also easily identified by appearance. They feature a six-bolt front face and a longitudinally ribbed barrel case.
There is a GM version of the 242 as used in the H1 Hummer (1990- ) and the later H2. It features a different front face bolt pattern that is incompatible with the Jeep six-bolt styles. This GM version is rated at a stronger duty by virtue of its stronger output shaft. It may feature a 1" wide or a 1.25" wide chain.
Interestingly, New Venture documents show the 242 as being rated at 1486 ft. lbs. of torque. This is probably determined based on Full-Time position usage. Experience would say that this is a very conservative number for all other positions.

[Vassago]

There you go all the info you should need to make your own educated decison. All that information was taken from the Novak Conversion knowledge pages.


can a mod sticky this? this NP231 vs. NP242 topic comes up constantly.

[mortalenema]

Found some cool info here: New Venture Gear Transfer Case Chart | moose.ca

The New Venture Gear Numbering System

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 241.
The second number is the strength:
The NV 241 is designated “4″ in strength – tougher than the
NV 231, but 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.




All this 242 talk and reading the last JP Mag has me thinking about the 242AMG in the H1, and what it would take to give it 2wd and adapt it to my XJ.

I agree, this might make a good sticky.

[xjfever]

Originally Posted by mortalenema

I've never had a reliability issue with a 242. I admit the 231 is marginally stronger. The real advantage to the 231 is aftermarket support. You can build a 231 stronger and SYE it more cheaply than a 242. If you live somewhere where the roads are an icy mix much of the year, the 242 is great. I have never had u-joints disintegrate on the 242 equipped Jeeps I've driven over the years. All my 231 equipped Jeeps have had u-joint issues. And, yes, I used 4wd correctly. I always shifted out when not needed. It's just that you can't always pull out of 4wd in time to stop a little binding/wear and tear. I blame Minnesota. The road surface is always the opposite of what selection you have on your TC.

I didn't mean to make it sound likethe 242 was a problem or nothing like that. I was just saying the 231 was a bit stronger and had less parts to worry about. I was afraid the OP was thinking the 242 may be a better t-case and wanted him to know it wasn't an upgrade in strength or anything that it just had the fulltime option. Down here in the south the 242 isn't an upgrade at all like it would be where there is snowy, icy roads for a good bit of the time. And the aftermarket support for the 231 is much better, but I would still most likely want the 242 in the northern part of the country.

[Bain98xj]

ok thanks guys.. well i think im just gonna take the 242 and keep it just in case i ever need it...