Adapting AX15 transmissions to 1976-1986 Jeep T150, T18, SR4, T4, T5, T176 bellhousings.
Adapting the 1976-1986 AMC Bellhousings to the Jeep AX15 & New Venture 3550 Transmissions
This conversion kit joins the popular AX15 and NV3550 overdrive transmissions to the series of AMC bellhousings made between 1976 and 1986 for a variety of OEM transmissions. This affordable and straightforward method allows the installer to retain the bellhousing they already own, and in many cases, the existing clutch and its release system. Its implementation is simple and effective.
Product & Features
The adapter is precision designed, and expertly CNC machined from 6061-T6 aluminum. Its thick cross-section provides ample thread engagement and high structural integrity. Precision indexing is achieved through locating dowels to the transmission and bearing retainer to the bellhousing.
Contents
Included are the adapter, bearing retainer (which serves as a centering index for the 76-86 AMC bellhousing and clutch release bearing sleeve) and required hardware.
Applications & Compatibility
This adapter assembly is compatible with the following AMC bellhousings:
- T150 & T18 version (1976-1979)
- If you have this version, existing holes will be used and clearanced for new fasteners
- SR4, T4 & T5 version (1980-1986)
- If you have this version, it will be necessary to drill and clearance for new fasteners
- T176 version (1980-1986)
- If you have this version, existing holes will be used and clearanced for new fasteners
The Jeep T150/T18 Bellhousing
If you don’t have one of the above bellhousings, but have the factory 1994-2004 4.0L to AX15 / NV3550 bellhousing,
Jeeps
This conversion is compatible with CJ7 and longer Jeeps. CJ5 Jeeps do not have a long enough wheelbase for the longer, five-speed transmissions.
These are strong transmissions and Full Size Jeeps such as Wagoneers, J-Trucks, etc. are conversion candidates for them unless used for more aggressive driving or heavy work situations.
Engines
AMC I6 & V8’s
All AMC engines made from 1972-2006 are compatible with the above bellhousings and therefore this conversion, including the 232, 258 & 4.0L I6 as well as the 304, 360 & 401 V8’s.
The Jeep / GM Iron Duke 2.5L bellhousing is also compatible with this conversion; some ancillary pieces will vary a bit but the adapting process is the same.
Flywheel
The factory flywheels on all of the above engines are acceptable. Most will accept the recommended 10-1/2” clutch. There are instances of larger clutches in some trucks. If you have one of these applications the clutch diameter will need to match. The Iron Duke will also need the clutch matching its flywheel.
Clutch
Novak’s hydraulic release slave cylinder kit.
The factory pressure plates, whether three-finger or diaphragm, are compatible with this adaptation. However, 1976-1979 (T150 & T18) clutch disc hubs have a 1-1/16″ spline diameter that is not compatible with the 1-1/8″ input shafts of the AX15 & NV3550. The proper clutch disc will be required and can be purchased separately below, or combined with a new pressure plate.
The factory clutch release arms and their linkages can be retained, including mechanical bellcrank style linkages, or hydraulic clutch release systems, whether factory or aftermarket retrofit.
Transmission Versions
All versions of the AX15 & NV3550 are compatible. However, 1994 and later AX15’s and all NV3550s will require a minor modification to their input bearing retainer. Earlier AX15s that featured the concentric internal throwout slave bearing do not require this modification. This is also compatible with Novak’s new, upgraded, stronger AX15 transmissions which come assembled to the extent possible with all parts ordered together.
Features
The adapter is precision designed, and expertly CNC machined from 6061 T6 aluminum. Its thick cross-section provides ample thread engagement and high structural integrity. Precision indexing is achieved through locating dowels to the transmission and bearing retainer to the bellhousing. Adapter thickness is just under 1” and the transmission is 16.5” long giving a 17.5” overall length from the front face of the adapter to transfer case mounting flange. The OEM AX15 bellhousing and associated shaft stickout of 7.5” is 1” longer than a standard 6.5” AMC bellhousing which lines things up perfectly with the adapter plate installed giving standard dimensions to the front of the adapted assembly. 10 input splines at 1-1/8” diameter and a pilot diameter of either .59 (early) or .75” (late) are accommodated by the correct pilot bushing and clutch specified below.
