Advance Adapters 50-6403 User Manual

ADV ANCE ADAPTERS INC. P/N: 50-6403

P.O. Box 247, 4320 Aerotech Center Way New Item: (11/93)
Paso Robles, CA 93447 PAGE 1 OF 3
Telephone: [phone] Fax: [phone] Page Rev . Date: 03-14-01

GM TH400 AUTOMATIC TO

JEEP NP231 TRANSFER CASE-23 SPLINES

KIT CONSISTS OF:

No. Qty Part No. Description

1. 1 51-6400 ADAPTER HOUSING (Ref: 711164) (Assembled by AA)

2. 1 52-3200 OUTPUT SHAFT (Ref: 711332)

3. 1 52-6301 SPUD SHAFT (23 Splines) (Assembled by AA)

4. 1 716308 BEARING (#6209) (Assembled by AA)

5. 1 716450 SNAP RING (GM #378-5205) (Assembled by AA)

6. 1 716456 SNAP RING (Assembled by AA)

7. 1 716510 GASKET (GM #862-4709)

8. 1 716517 GASKET

9. 6 723701 HEX NUT 3/8"-16

10. 6 723704 3/8" LOCK WASHERS

11. 6 723711 STUD BOLT 3/8"-16 x 2" LG

12. 6 723722 H.H.C.S. 3/8"-16 x 1-1/4" LG

13. 1 JP001 JEEP INSTRUCTION MANUAL

OPTIONAL ITEMS:

No. Qty Part No.

1 716008 CROSSMEMBER MT

This kit is for replacing the AX15 5-Speed transmissions.

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.

ADV ANCE ADAPTERS INC. P/N: 50-6403

P.O. Box 247, 4320 Aerotech Center Way New Item: (11/93)
Paso Robles, CA 93447 PAGE 2 OF 3
Telephone: [phone] Fax: [phone] Page Rev . Date: 03-14-01

GM TH400 AUTOMATIC TO

JEEP NP231 TRANSFER CASE-23 SPLINES

GM TURBO 400 3 SPEED AUTOMATIC

The GM TH400 has a case length of 24-3/4", 13 bolts for holding the oil pan in position and is available in 3 different engine
to transmission bolt patterns. Make sure you have selected the proper TH400 for your particular engine. The AMC TH400
case when used with the Chevy engine will require adapter Kit No. 716133. 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 these transmissions
have been equipped with, but our new output shaft will be interchangeable with your factory output shaft. The new shaft
supplied with your kit should be installed by a competent mechanic. The speedometer gear is normally located in the
tailhousing, but when adapting it to the transfer case, the location will change to the backside of the transfer case. The
rear transmission support will now be located on the new adapter housing.

When installing the new transfer case adapter, make sure that the coupler 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 our 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.

When assembling the adapter housing to the transmission case, we have provided you with a new gasket to prevent fluid
leakage. This gasket is a stock GM item that is used on all TH400 installations.

If you have selected a transmission that has the old style modulator, then we recommend the use of the Advance Adapter
adjustable modulator, Part No. 716010. This will also allow for additional driveshaft clearance.

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.

ASSEMBLY

*Some components of this kit should be pre-assembled. If the casting, bearing, and spud shaft are not pressed

together then follow steps 1 to 8. If your parts are assembled, proceed to step 4.

This kit comes pre-assembled with the bearing, snap rings, and spud shaft installed in the casting. The bearing and

1.
spud shaft are a press fit. The spud shaft is pressed to the bearing and the snap ring installed to retain the spud shaft
properly. The bearing and spud shaft assembly are also a press fit into the adapter housing. The bearing and spud
shaft are pressed into the casting from the transmission side. Take note that the external splined side of the spud
shaft is facing the circular six bolt side of the adapter. This assembly is retained with the provided snap ring.

2. The TH400 output shaft provided must be installed by an experienced transmission tech.

3. Trial fit the adapter assembly to the transfer case. Check for proper spline engagement and shaft depth. The casting
and transfer case should fit together flush with no gaps. If you have a 1/8" gap between the casting and transfer
case. DO NOT "SUCK UP" THE TWO ITEMS! SEVERE DAMAGE WILL OCCUR. Call Advance Adapters
and they will send you the correct spud shaft.

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.