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Transfer Case Identification for 1987-2007 Jeep Vehicles
New Process 200 Series Transfer Cases
New Process transfer cases used in late model Jeeps are always a
left-hand drop configuration and have the same circular bolt pattern
as the Dana 300. One of the differences between the Dana 300 and New
Process transfer case is the rotation. The stock rotation on the New
Process transfer case depends on the year of the vehicle and the stock
transmission used. The rotations are approximately 13 or 23 degrees.
The input splines on these transfer cases vary from 21 to 23 splines,
and the transmission that is mated to these transfer cases had either
a long or flush output shaft length. It is crucial that you identify
the correct spline length and tooth count before ordering any
There are numerous styles of New
Process transfer cases, and you must be very careful in making your
identification of such. The first units were the NP207s, and they were
used in the early model Cherokee Jeeps. The full size Jeep trucks and
Grand Wagoneers used the NP208. Jeep soon added the NP231 which
replaced the Model 207 in 1987. A Model NP242 was also added for the
full time 4WD models.
With all of the variations in
model numbers, the only variation that we see concerning transmission
adaption is the size and tooth count of the transfer case input spline.
As mentioned in the second paragraph, the New Process transfer case
has two basic spline counts and each spline count has two different
lengths. Both the NP207 and NP231 transfer cases were available with
these two different input splines. The input splines of the transfer
case can be changed if necessary, but the complete transfer case will
The easiest way that we have
found to identify the proper transfer case input is by identifying the
stock transmission that Jeep used. The 21 and 23 spline output shafts
vary on different transmission models. The AX15 transmission is always
23 spline and protrudes 1/2" beyond the face of the transmission. The
Torqueflite and NV3550 are normally a flush 23 spline. The AX4 & AX5
always have 21 splines and is flush with the back of the transmission
adapter until 1996; and then in 1997, the AX5 output shaft was
lengthened to a 1/2” stickout past the tailhousing adapter. The
Peugeot transmission is always 21 splines and protrudes 1/2" beyond
the back of the transmission adapter housing. We have seen the AW4
automatic transmission in both a long 21 & 23 spline.
Starting with the JK in the 2007 model year the 231
was replaced with the 241 model Transfer case. Externally they look
the same except for a slight size difference making the 241 larger.
Factory Transfer Cases: These pages cover the transfer cases used
in Jeeps over the years. Transfer cases are arranged by the most
recently introduced first.