Advance Adapters 50-3205 - Manual (Page 2)

GM 2WD 4L80E AUTOMATIC TO
FORD NP205 TRANSFER CASE
ADVANCE ADAPTERS INC. P/N: 50-3205
P.O. Box 247, 4320 Aerotech Center Way
Paso Robles, CA 93447
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Telephone: (800) 350-2223 Fax: (805) 238-4201 Page Rev. Date: 12-12-13
SPECIAL NOTE: The components packaged in this kit have been assembled and machined for specific type of conversions. Modifications to any of the components will
void any possible warranty or return privileges. If you do not fully understand modifications or changes that will be required to complete your conversion, we strongly recommend
that you contact our sales department for more information. This instruction sheet is only to be used for the assembly of Advance Adapter components. We recommend that a
service manual pertaining to your vehicle be obtained for specific torque values, wiring diagrams and other related equipment. These manuals are normally available at automotive
dealerships and parts stores.
GM 4L80E AUTOMATIC
This transmission was designed by GM to replace the GM TH400 transmission. Like the TH400, the 4L80E
has a 32 spline output shaft. The major difference of the 4L80E is that the transmission index diameter is
different than the TH400. We have seen 5 different output shaft lengths that were used in the 4L80E transmis-
sion. This kit is designed to fit a 2WD output with a long slip spline.
The early 4L80E transmission up to 1995 is normally equipped with an internal reluctor ring on both the trans-
mission input shaft and output shaft. The computer takes both of these readings for the proper shifting and
operation of this transmission. We have always ignored the reluctor ring requirement for this transmission
since it is internally regulated. We have now learned that the rear reluctor ring is not always installed into the
transmission. The basic rule of thumb is 4WD transmissions up to 1996 should have a rear reluctor ring in the
main transmission case. All 2WD transmissions should have the rear reluctor in the main transmission case.
The 1997 & newer 4WD 4L80E transmissions have a sensor provision; however, the reluctor ring in the
transmission is left out.
Note: The information on years and models of the 4L80E transmission mentioned in the above section was
obtained from various sources. You should always verify what your transmission is equipped with before
beginning a conversion, especially with the 4L80E transmission.
This adapter kit includes a new input gear for the NP205 transfer case. This gear has a 32T internal spline and uses
the stock Ford bearing. This gear is a stock GM item that was used on 1-ton vehicles only. Be sure to inspect the
seal area provided in the adapter housing to make sure that it has the proper contact on the new sleeve and gear supplied.
When installing the new transfer case adapter, make sure that the new input gear and the output shaft do not bottom
out. We have found on occasion that a transmission output shaft may be slightly longer than we have allowed for and
when coupling into out new spud shaft, we find a small amount of interference. The adapter housing and spud shaft
must be assembled to the back of the transmission without interference.
DO NOT FORCE THE NEW
TAILHOUSING ONTO THE TRANSMISSION. If assistance is needed, please feel free to call the number listed
above.
All installations will require the use of a transmission cooler. The cooler can be either installed in the radiator or a remote
location is acceptable.
The 4WD linkage mounting bracket will need to be relocated further forward to allow for the added length of the new
transmission.