Advance Adapters 50-0410 User Manual

ADVANCE ADAPTERS INC. P/N: 50-0410

P.O. Box 247, 4320 Aerotech Center Way New Item: (5/98)
Paso Robles, CA 93447 PAGE 1 OF 3
Telephone: [phone] Fax: [phone] Page Rev. Date: 08-10-12

GM 4L80E AUTOMATIC TO

NP205 TRANSFER CASE 1971-79

KIT CONSISTS OF:

No. Qty Part No. Description

1. 1 51-0410 ADAPTER (INDEX DIAMETER 4.8")

2. 1 716044 NP205 INPUT GEAR w/ 32T INTERNAL SPLINES

3. 1 716315 BEARING (for 716044 input gear)

4. 1 716458 SNAP RING (for 716044 input gear)

5. 1 716511 "O" RING (GM #135-8899)

6. 1 716572 NP205 GASKET

7. 1 716754 NATIONAL SEAL (#4435) (Installed by AA)

8. 6 720028 10mm 1.5 x 35mm LONG (May need to be shortened)

NOTE:

THIS KIT TAKES A SPECIAL 2WD OUTPUT SHAFT (FULL SPLINE). PLEASE REFER TO THE O.E.M.
PART NUMBERS ON PAGE 2 BEFORE ORDERING OR OBTAINING YOUR TRANSMISSION.

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.

ADVANCE ADAPTERS INC. P/N: 50-0410

P.O. Box 247, 4320 Aerotech Center Way New Item: (5/98)
Paso Robles, CA 93447 PAGE 2 OF 3
Telephone: [phone] Fax: [phone] Page Rev. Date: 12-26-06

GM 4L80E AUTOMATIC TO

NP205 TRANSFER CASE 1971-79

GM 4L80 4 SPEED AUTOMATIC OVERDRIVE

The GM 4L80 has a case length of 26", 17 bolts for holding the oil pan in position. The rear side of the transmission case
will have a hex shaped bolt pattern that uses 6 bolts. There are several various lengths of output shafts that the transmission
has been equipped with and you will need the 6-1/2" slip yoke output shaft GM# 24218219 (1991 to 1996) or GM#
24204289 (1997 to 2007). This shaft is fully splined. Any other 2WD output shaft will not work.

This adapter kit includes a new input gear and bearing for the NP205 transfer case. This gear has a 32T internal spline
that requires a larger bearing than most Chevy NP205 transfer cases. This gear is a stock GM item that was used on one
ton vehicles only. The transfer case must be completely disassembled and the bearing bore size enlarged to accommodate
the new bearing furnished. 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.

We have provided a new gasket to be installed between the adapter plate and the transfer case to allow proper load heights
on the bearing. This gasket is a stock GM component, and it will require some trimming to fit over the new larger bearing.

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 the output shaft and transfer case input sleeve may bottom out if the shaft was not cut
to the proper length. 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 transmission shift control can either be a Hurst floor mounted type shifter or sometimes the
existing column shift can be modified on certain applications. The adapter bolts directly to the back of the 4L80
transmission using 6 socket head cap screws that must be torqued to 25 ft./lbs. The original cooler lines and fittings will
line up with the transmission. The original flexplate and converter can be retained. The transmission shift linkage can
also be retained. The 4WD linkage mounting bracket will need to be relocated further forward to allow for the added length
of the new transmission. The original transmission crossmember will need to be relocated on the frame rails approximately
3-1/2" further back.

The 4L80E transmission is normally equipped with an internal reluctor ring on both the transmission input shaft and
output shaft. The computer takes both of these reading 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 had a sensor
provision; however, the reluctor ring in the transmission was left out. Make sure the transmission you plan on using has

the rear reluctor ring installed for proper operation of this transmission.

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
with the 4L80E transmission.

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.