Advance Adapters AX15 - Manual (Page 39)

39
GM NP205 1985-91 (32 spline T/C circular 6 bolt pattern) to GM 4WD NV4500: GM NP205 1985-91 (32 spline T/C circular 6 bolt pattern) to GM 4WD NV4500: GM NP205 1985-91 (32 spline T/C circular 6 bolt pattern) to GM 4WD NV4500: GM NP205 1985-91 (32 spline T/C circular 6 bolt pattern) to GM 4WD NV4500: GM NP205 1985-91 (32 spline T/C circular 6 bolt pattern) to GM 4WD NV4500:
This NP205 was originally coupled to a SM465 or TH400: Found in 1985-91 vehicles, this transfer case has a long input gear stickout
of approximately 3.50”, and a female 32 spline input. The bolt pattern is a circular-six configuration. Transfer cases with this long
stickout will require a spacer adapter or a change out to the short version GM input gear when coupling to the GM NV4500.
The NV4500 has the correct bolt pattern and spline count as the NP205 transfer case. The problems that
come into play are the spline engagement and the transfer case shift rail clearance. To couple the two
units together, you have two options. First, we offer a spacer plate that is 1.625” long. This plate has
a clearance notch for the NP205 transfer case shift rod along with the necessary length to compensate
for the spline length difference. The second option is to change out the input gear on the NP205
transfer case to the shorter 1.5” long stickout length. If you decide on this option, the stock NV4500
tailhousing must also be modified to allow for clearance on the transfer case shift rails. We do not
offer any transfer case shifter brackets designed specifically for the application; however, the bracket
we produce for the earlier NP205 transfer cases will give you a good starting point to obtain the linkage
pivot point. For the listed bellhousing components, refer to the following page.
P/N 51-6910 - Spacer adapter
P/N 716038 - NP205 input gear and bearing (short stickout)
P/N 715529 - Transfer case linkage bracket (modifications are required)
GM NP208/NP241 to GM 4WD NV4500:
The New Process 208 is a chain-driven transfer case. This is a cast aluminum transfer case. Compared to the NP203 and NP205,
the lightweight cast aluminum housing of this transfer case is easier to handle. This transfer case is a good gear box with a low
ratio of 2.61:1. The weakest part of this transfer case is that the shifter fork wears easily, causing shifting problems. This transfer
case was used in production vehicles manufactured from GM, Dodge, and Ford. Identifying the GM version is done easiest by the
round identification tag affixed to the case. This transfer case has a right hand drop configuration, synchronized shifted, and has
a rear slip yoke. The GM NP208s have either a female 27 tooth input spline (originally coupled to a 700R transmission), or a female
32 spline input (originally coupled to a SM465 or TH400 transmissions).
The New Process 241 is also a chain-driven transfer case. This is a cast aluminum transfer case. This transfer case is a good
gear box with a low ratio of 2.71:1. Since this is the newest design of the New Process transfer case models, the weak links of this
transfer case are few and far between. GM uses this transfer case in both right hand and left hand drop configurations. Even with
these two configurations, the adapters we manufacture work the same since the bolt pattern on this transfer case is symmetrical.
This transfer case is used in production vehicles manufactured from GM, Dodge, and Ford. Identifying the GM version is done easiest
by the round identification tag affixed to the case. This transfer case is normally a right hand drop on vehicles with a solid front axle,
and a left hand drop on vehicles with I.F.S. The GM NP241s have either a female 27 tooth input spline (originally coupled to a 700R
or 4L60E transmission), or a female 32 spline input (originally coupled to a SM465, TH400, or 4L80E transmission).
Both of these transfer cases bolt directly to the stock GM 4WD tailhousing adapter. An area od concern with these transfercases
is the crossmember used by GM. Vehicles 1981-1984 used a crossmember with a drop; the stock adapter having a long foot to
couple to this crossmember support. The 1985 & newer vehicles came with a crossmember that was tucked up tightly to the frame
rails, thus requiring a short foot on the adapter housing. The stock NV4500 housing has a mounting foot that is similar to that of
the later model crossmembers.
The bellhousings to fit the NV4500 to the GM blocks are listed at the end of this section. Caution should be used
when using one of our full bellhousings due to the close front driveshaft clearance on the I.F.S. axles. Our
bellhousings can be modified to fit; however, the stock GM bellhousing we offer will provide a cleaner installation.
700R/4L60E to NP208/241
700R/4L60E to NP208/241 (short foot)
SM465 to NP208/241 (long foot)
SM465 to NP208/241 (short foot)