AX15 Adapter

Adapting the Chevrolet & GM SBC, LS and Jeep 225 / 231 Standard Shift Engine Bellhousings to the Jeep AX15.

This Novak Adapters conversion kit joins the popular AX15 overdrive transmission to the standard GM pattern bellhousings 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 extremely effective.

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.

Kit includes the GMAX15 adapter plate, bearing retainer (which serves as a centering index for the GM bellhousing and clutch release bearing sleeve) and required hardware.

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 are great candidates for them unless used for more aggressive driving or heavy work situations.

Nearly all GM Generation I-III engines are compatible with this conversion, including Chevrolet Small Blocks, Gen III+ V8's, Chevrolet V6's and Chevrolet I6 engines. Buick, Olds, Pontiac, and other GM engines are compatible with this adapter assembly if you have a standard shift classic GM bellhousing and flywheel for your engine. Even some of the front wheel drive and odd application engines could be made to work with this adapter using certain factory or aftermarket bellhousings sharing this common rear pattern.

The factory flywheels on all of the above engines are acceptable with some notable exceptions. The LS architecture (Gen III & IV GM V8) engines have a crank offset of 0.400” forward that necessitates a special flywheel (available separately via the pull-down menu at the right side of this page). There are a few rare exceptions to that rule in the 4.8L & 6.0L engines (from the heavier 3/4+ ton truck applications) to be wary of as they are special cases in themselves and very specific in their flywheel requirements. The 400 small block and some Gen II examples are externally balanced and require special consideration. Make sure the flywheel matches the engine, fits in your bellhousing and will accept an appropriate clutch.

The factory pressure plates, whether three-finger or diaphragm, are compatible with this adaptation. However, the clutch will need to match both the flywheel and be compatible with the bellhousing. Not all bellhousings and flywheels will accept the larger clutches. 153 tooth flywheels are limited to the more difficult to source 10-1/2” clutch and changing over requires the appropriate bellhousing, flywheel, clutch and starter. Our advice is to plan ahead and not get stuck with difficult to source parts simply because you may have one piece of the puzzle.

The factory clutch release arms and their linkages can often be retained, including mechanical bellcrank style linkages, or hydraulic clutch release systems, whether factory or aftermarket retrofit.

All versions of the AX15 are compatible.

Pilot Bushings is required for all installations. Please choose your applicable engine and transmission combination in the pull-down menu to the right.

Transmission Rear Mount: The AX15 and NV3550 feature a threaded base for support and isolation of the transmission and transfer case. Factory style isolator mounts are difficult to work with in any situation other than as a direct factory replacement. Novak has engineered a universal style rear mount that is easy to affix to a variety of Jeep crossmembers and is very strong and highly adjustable. We recommend it in any retrofit situation. 

Flywheel: This is a beautiful piece and necessary for proper operation on LS based engines. They must have the LS crank offset to work properly. These will accept both the 11” and 12” clutch.  The LS Bolts are necessary for installation of the LS Flywheel.

Transfer Cases: will accept all AX15 transfer cases, or by selecting an adapter to the right, can be mated to the Dana 300 or Dana 20 Transfer Cases.

**Note: Bellhousing shown is 225 / 231 style that is compatible with this kit (Bellhousing is NOT included).  225 and 231 applications must use the BOP 225 / 231 to T14 bellhousing (casting 9774035), and do not reuse the original adapter between the engine and transmission.

 

 

• Fits Jeeps with 225 or 231 V6
• Fits Jeeps with SBC / LS Conversion
• Models All with AX15 Conversion
• Will NOT Fit CJ5 (The CJ5 is Too Short of a Wheelbase)
• Includes: adapter plate, bearing retainer and required hardware