700R-4 X JEEP NP231 21 spl upgrading to 87-95 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. Introduced in 1988, the Jeep NP231 is a part-time transfer case became the standard for XJ and YJ models. It was also used in six cylinder ZJ models through 1995. 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).

Notes:

• On Jeeps 1995 & newer, New Process used a different planetary assembly. This late model transfer case can be identified by one of three case model numbers: 52097-894, 52098-361 & 52098-540.

Bill Of Materials

• GM 700R/4L60E NYLON BUSHING / 716082
• GM AUTO TRANSMISSION O RING / 716511
• INPUT GEAR-NP231 23 SPLINE SHORT PRE 95 W/716325A / 716054
• ADAPTER- TH350 TO JEEP NEW PROCESS / 51-6800
• SHAFT- 700R4 OUTPUT TO JEEP 23 SPLINE / 52-9101
• GASKET-N.P.208 TRANSFER CASE / 716517
• LOCK WASHER 3/8 ZINC / 723704
• STUD BOLT 3/8 -16 X 2 LG B7 / 723711
• BOLT 3/8 -16 X 1.25″ SHCS ZNC / 723730
• NUT 3/8 -16 PLATED GRD 5 / 723701
• SEAL CR#19466 / 716729
• SEAL-NP231 STOCK REPLACEMENT / 716760
• 10mm-1.5THR X 40mm S.H.C.S. black oxide / 720046