swapping from np242 to np231
Thread Starter
Seasoned Member
Joined: Aug 2017
Posts: 273
Likes: 14
From: Southwest Arkansas
Year: 1994
Model: Cherokee(XJ)
Engine: 4.0
I think I'm just gonna go big or go home and do the whole shaft kit. I can't drill and tap a straight hole to save my life. lol I've got a yj yoke coming that'll ease my mind as far as spline engagement until I get everything pieced together, going to get a new chain and bearings, shift fork pads, etc.. while I'm in it. Prob an adams driveshaft, I just want to have everything I'll need before I tear into it so it'll be the least amount of downtime.
CF Veteran
Joined: Oct 2018
Posts: 1,096
Likes: 166
From: Hunt County Texas
Year: 1995
Model: Cherokee (XJ)
Engine: 4.0L
How weak is the 242, or is it? I've been reading and reading, Getting conflicting answers everywhere. People say they break easy, people say they're strong. Is it worth dumping the $ into it doing a rebuild with sye and a hd chain? I like the thought of having awd, but here in south arkansas we very rarely get snow, and the only other time I may use it is if I get on a sloppy dirt backroad right after it rains.
Its plenty strong enough. Its been used in vehicles larger, heavier and more powerful than any factory XJ. Examples being the Dodge Durango and military and civie HMMWV
New Venture Transfer Case Numbering System
Decoding NP/NVG transfer cases is fairly simple,
once you know the current system. Each tcase has
a 3 number call out, like 231, 241, 242, etc.
These three numbers will tell you the basics.
First Number: The number of speeds. If it is a
standard high range, neutral, low range transfer
case, the number is 2. If it is a single speed
with no low range, like a 133, it gets a 1.
Second Number: The size of the case, physically,
and has a lot to do with how strong the case is.
The case sizes current are: 2, 3, 4, 6, 7. With
22X series being the smallest and 27X series being
the largest.
Third Number: This is where it gets confusing.
The third number tells you what type of 4wd
system is in the transfer case. Current systems
are designated by: 1, 2, 3, 4, 6, 7.
I'll explain:
1 - Part time (PT) transfer case, manually
shifted. When in 4wd, front and rear driveshafts
are locked together. If its a 2 speed tcase, then
it would have 4 positions, 2wd, 4wd, N, 4 low
part-time (LPT). These cases are shifted by a
lever on the floor.
Example: 231, 241, 261, 271
2 - Part time transfer case plus Full time (FT),
manually shifted. A geared differential is used
to allow the driveshafts to turn at different
speeds, while still applying torque. Some are 4
position and some are 5. 4 position have 4FT,
4PT, N, 4LPT. 5 position boxes get a true 2wd
where the differential is bypassed and all the
torque goes to the rear driveshaft. These cases
are shifted by a lever on the floor.
Example: 242, 242HD, 242AMG
3 - Part time (PT) transfer case, electrically
shifted. Everything is the same as a -1-, except
an electric motor is used to shift the transfer
case. Instead of a lever on the floor, you have a
button or a dial on the dash.
Example: 133, 233, 243, 263, 273
4 - Part time transfer case plus Full time (FT),
electrically shifted. Everything is the same as a
-2-, except an electric motor is used to shift
the transfer case. Instead of a lever on the
floor, you have a button or a dial on the dash.
Example - 244
5 - This is found on 2005+ Jeep Grand Cherokees
with the Hemi. (see below)
6 - Active on demand System. Front and rear axles
are constantly monitored electronically to detect
any differences in speed due to wheel slippage.
When a speed difference is detected, a computer
signals the transfer case clutch pack to engage.
Torque transfer is transparent to the driver,
meaning the driver can tell it happened, like all
four wheels are now pulling, but you didn't have
to pull a lever or turn a dial to activate it.
Example: 226, 236, 246
7 - Progressive on demand system. The vehicle
operates in 2WD. When traction is lost by one of
the driving wheels, power is automatically
transferred to the other axle. Torque transfer is
transparent to the driver, meaning the driver can
tell it happened, like all four wheels are now
pulling, but you didn't have to pull a lever or
turn a dial to activate it.
Example: 247
Decoding NP/NVG transfer cases is fairly simple,
once you know the current system. Each tcase has
a 3 number call out, like 231, 241, 242, etc.
These three numbers will tell you the basics.
First Number: The number of speeds. If it is a
standard high range, neutral, low range transfer
case, the number is 2. If it is a single speed
with no low range, like a 133, it gets a 1.
Second Number: The size of the case, physically,
and has a lot to do with how strong the case is.
The case sizes current are: 2, 3, 4, 6, 7. With
22X series being the smallest and 27X series being
the largest.
Third Number: This is where it gets confusing.
The third number tells you what type of 4wd
system is in the transfer case. Current systems
are designated by: 1, 2, 3, 4, 6, 7.
I'll explain:
1 - Part time (PT) transfer case, manually
shifted. When in 4wd, front and rear driveshafts
are locked together. If its a 2 speed tcase, then
it would have 4 positions, 2wd, 4wd, N, 4 low
part-time (LPT). These cases are shifted by a
lever on the floor.
Example: 231, 241, 261, 271
2 - Part time transfer case plus Full time (FT),
manually shifted. A geared differential is used
to allow the driveshafts to turn at different
speeds, while still applying torque. Some are 4
position and some are 5. 4 position have 4FT,
4PT, N, 4LPT. 5 position boxes get a true 2wd
where the differential is bypassed and all the
torque goes to the rear driveshaft. These cases
are shifted by a lever on the floor.
Example: 242, 242HD, 242AMG
3 - Part time (PT) transfer case, electrically
shifted. Everything is the same as a -1-, except
an electric motor is used to shift the transfer
case. Instead of a lever on the floor, you have a
button or a dial on the dash.
Example: 133, 233, 243, 263, 273
4 - Part time transfer case plus Full time (FT),
electrically shifted. Everything is the same as a
-2-, except an electric motor is used to shift
the transfer case. Instead of a lever on the
floor, you have a button or a dial on the dash.
Example - 244
5 - This is found on 2005+ Jeep Grand Cherokees
with the Hemi. (see below)
6 - Active on demand System. Front and rear axles
are constantly monitored electronically to detect
any differences in speed due to wheel slippage.
When a speed difference is detected, a computer
signals the transfer case clutch pack to engage.
Torque transfer is transparent to the driver,
meaning the driver can tell it happened, like all
four wheels are now pulling, but you didn't have
to pull a lever or turn a dial to activate it.
Example: 226, 236, 246
7 - Progressive on demand system. The vehicle
operates in 2WD. When traction is lost by one of
the driving wheels, power is automatically
transferred to the other axle. Torque transfer is
transparent to the driver, meaning the driver can
tell it happened, like all four wheels are now
pulling, but you didn't have to pull a lever or
turn a dial to activate it.
Example: 247
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