700R-4 X JEEP NP231 21 spl upgrading to 95 and newer 23 spl

Advance Adapter

The 700R automatic transmission adapter to the Jeep New Process 231 is 1.50″ in length. The adapter material is 356 T6 heat treated aluminum alloy and has a provision for a transmission mount. The adapter kit includes an adapter housing, new 700R4 output shaft, upgraded NP231 (23 spline) input gear, bearing, snap rings, o-ring, seal, gasket, fastening hardware and adapter instructions.

Transfer Case

The adapter assembly will fit the Jeep NP231 transfer case with a 21spline input shaft. The Jeep NP231 is a part-time transfer case became the standard for XJ and TJ models. It was also used in six cylinder ZJ models. Chain driven with a 2.72:1 low range, it’s reliable even with more than stock horsepower applied.

Transmission

This kit is designed for exclusive use with our new main shaft that fits the 700R-4 / 4L60 manufactured thru 1996. The overall case length of the transmission is 23.375″, has a non-removable bell housing, and a 4 bolt square rear case. Late model 4L60E automatics will have a removable bell housing and a 6 bolt hex pattern rear case. The late model automatic will require an additional Advance Adapter to work with this kit (50-0405).

Bill Of Materials

• 10mm-1.5THR X 40mm S.H.C.S. black oxide / 720046
• SEAL-NP231 STOCK REPLACEMENT / 716760
• SEAL CR#19466 / 716729
• NUT 3/8 -16 PLATED GRD 5 / 723701
• BOLT 3/8 -16 X 1.25″ SHCS ZNC / 723730
• STUD BOLT 3/8 -16 X 2 LG B7 / 723711
• LOCK WASHER 3/8 ZINC / 723704
• GASKET-N.P.208 TRANSFER CASE / 716517
• SHAFT- 700R4 OUTPUT TO JEEP 23 SPLINE / 52-9101
• ADAPTER- TH350 TO JEEP NEW PROCESS / 51-6800
• 23T NP231 T/C INPUT GEAR w/ pocket brng. 5-1/8 oal / 716095
• GM AUTO TRANSMISSION O RING / 716511
• GM 700R/4L60E NYLON BUSHING / 716082