50-9103 : GM 700R4 & 4L60 to Jeep NP231 ((21 spline)) Adapter Kit (#50-9103)

Retail Price: $505.87

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.


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).


  • 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.

1)1987-06 General Engine Conversion Information

4) New Process 231

3. GM 700R4 & 4L60

Top Reviews


by Dennis Davenport, from Fayetteville NC

700r4 adapter

The products have always been top of the line, over the last 40 years have always had great service, but for some reason this time around it took two mo. from order to delivery. running a shop this is not a very good option, most of my customers do not want to wait that long, and i hate having there rigs tied up up for that long, it takes up my time and i loose a working bay in the shop for two mo with no income from that bay.

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