Adapting the

Ford Windsor V8 Engines

to the

Jeep AX15 Transmission

Jeep Adapter kit to GM Bellhousings

Kit FMAX15, adapting Ford bellhousings to the Jeep AX15 transmission

This conversion kit joins the popular AX15 overdrive transmission to the classic, standard shift Ford bellhousings. This affordable and straightforward method allows the installer to use the Ford V8 bellhousing. Its implementation is straightforward.

The adapter is precision designed and expertly CNC machined from alloy 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. This adapter is just under 1” thick 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. 10 input splines at 1-1/8” diameter and a pilot diameter of either 0.59" (early) or 0.75" (late) are accommodated by the correct pilot bushing and clutch specified below.

The adapter installs onto these transmissions with no change of input gear or other transmission internals. Cutting the transmission input shaft is not required as the adapter spaces the transmission properly for the GM crank and clutch assembly. A new pilot bushing is required for this assembly. See Related Products below for the one matching your Ford engine.

Kit Contents

Included is the adapter, bearing retainer (which serves as a centering index for the Ford bellhousing and clutch release bearing sleeve) and required hardware.

Applications & Compatibility


~1981-1991 Ford truck bellhousing

This adapter assembly is compatible with most Ford bellhousings using the standard Ford “butterfly pattern”. Numerous combinations were used over the years by Ford and the aftermarket. If using a mechanical linkage most anything that can be fabricated to fit will work so long as it retains the correct bolt pattern. Our preferred bellhousing is shown here and detailed on this page. The main reason is the ease of installing a hydraulic clutch slave assembly.

Compatible Jeeps

This conversion is compatible with CJ7 and longer Jeeps. CJ5 Jeeps do not have a long enough wheelbase for these 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.

Compatible Engines

289, 302, 351, 5.0L and 5.7L Ford Windsor engines all make for great Jeep power.

The Ford 289, 302, 5.0L, 351 & 5.8L (small block Ford) Windsor engine family are all compatible with this conversion. The use of a Ford "butterfly" bellhousing is required. There are some versions of Ford engines that fall outside this parameter and you’ll want to verify that you indeed have a matching combination. Of note are the very early Mustang engines and other of similar block pattern which used a different rear pattern and are not compatible without special adapter scattershield bells.

With some creativity, most of the Ford engines that will fit in a Jeep can be made to work with the AX15. There are bellhousings available for the Modular series engines including the 4.6/5.0 Coyote/5.4, etc. At this point we don’t offer support for all of these combinations but the adapter is universal once you have the right bellhousing.


The factory flywheels on the above engines are acceptable. Ensure that the flywheel and clutch match your engine combination. Discs can usually be substituted within standard pressure plates to match the required 10 spline 1-1/8” used by the Jeep AX15/3550. See Related Products below.


The factory pressure plates, whether three-finger or diaphragm, are compatible with this adaptation. Ensure that the pressure plate is compatible with your engine, flywheel, bellhousing and actuation components. The proper clutch disc will be required and can be purchased separately below.

The factory clutch release arms and their linkages can be retained and adapted as necessary. Again, the above recommended Small Block Ford Bellhousing combination has proven to be the easiest to convert using our hydraulic clutch release systems when using the Windsor style Ford small blocks.

Transmission Versions

All versions of the AX15 are compatible. However, 1994 and later AX15's will require a minor modification to their input bearing retainer. Earlier AX15's 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 parts ordered. They can be seen here and purchased below.

Related Products

Hydraulic release master kit for Jeeps
Hydraulic release master kit for Jeeps
Hydraulic release master kit for Jeeps
Hydraulic release adapter for Jeeps
AX15 & NV3550 Rear Mount
1976-1986 Jeep floor tunnel cover
Adapting NV3550 transmissions to Jeep Dana 300 transfer cases
Adapting NV3550 transmissions to Jeep Dana 18 & 20 transfer cases

Installation Requirements



A drill, 29/64” bit, and various smaller bits are required, in addition to typical mechanic's hand tools.


Setting the powertrain to the proper factory or conversion pitch angle - usually tilted down ~5 degrees (3-7 acceptable) is recommended.

Engines & Engine Mounting


Novak does not yet offer mounts for Ford engines in the TJ / LJ Jeeps to which the NV3550 is native. However, we do carry a universal style mount for other Jeeps in which this combination may be installed. See Novak's MMX Series engine mounts.


Driveshaft length changes may be required.

Some installers, concerned about the expense of new or modified driveshafts, attempt to let the existing driveshafts dictate engine, transmission and transfer case location, often to the detriment of the project. Our recommendation is to prioritize the correct position of drivetrain components over saving a few dollars which is usually regretted in the long run with compromised positioning.

Jeeps that require extensive travel or specialty-built driveshafts have this option available through several fabricators across the nation. These are normally specified after placement of the new transmission and measured at vehicle ride height. As the rear driveline gets shorter, it is often advantageous to us a Double Cardan or “CV style” rear shaft with the correct geometry at the axle to minimize vibrations and possible binding.


Use of factory axles is completely acceptable with this conversion. Axle upgrades are not necessary, but they may be chosen for reasons external to this transmission upgrade.

Also See