Adapting
Chevrolet & GM Generation I-III+ Engines
to the
Jeep AX15, NV3550 & NSG370 Transmissions
With the advent of quality five and six-speed transmissions in Jeeps, we now offer the possibility of marrying them to various Chevy and GM engines in a straightforward and sanitary manner using our block-to-bellhousing style adapter assembly.
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The Adapter
This plate style adapter is precision laser cut and machined. Included are the adapter, fastening hardware and instruction guide.
Precision CMM mapped and machined dowel locators and fastening points assure total concentricity for long transmission life.
The adapter is plated in black zinc for corrosion resistance and appearance.
Transmission Versions
This adapter is compatible with the:
This kit will work with either the earlier AX15 that uses the concentric, internal hydraulic throwout bearing, or the later style AX15 that uses the external slave cylinder.
Engines
The following Chevrolet & GM engines are compatible:
*Big Block V8's or other engines may not be appropriate for the strength of certain transmissions.
Installation
The adapter is easily and quickly installed onto the engine and transmission.
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Choosing Your Pilot Bushing
Depending on the transmission you have and the engine you choose, your pilot bushing will vary. See our Pilot Bushings page to choose this critical component for your conversion.
Your Clutch Assembly
You will use your GM flywheel, pressure plate and clutch disc. This adapter assembly is intended to work with factory height pressure plates. Use of a pressure plate with a non-standard hat height pressure plate will complicate the project, requiring you to use a different or modified throwout bearing, the height of which will be difficult to determine when using a transmission that features a non-detachable bellhousing.
For your reference, we use Jeep throwout bearing #53008342 with the later (external slave) AX15 and all 3550 and NSG370 transmissions.
Engines & Engine Mounting
These Jeep transmissions are likely to be relocated as much as 3" forward when attached to most V6 & V8 engines, due to firewall vs. block/head differences in the GM engines vs. the I6 engines. This is not difficult and shifter stick modifications (instructions included) are recommended to avoid body tunnel modifications and to keep your factory console and boot in the same location.
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| Novak's MM Series engine mounts, featuring excellent vibration dampening, superior strength and impressive adjustability - adjustable even after the engine is installed. The design and strength and affordability of our mounts are second to none. |
The Novak engine mounting system offers the best designs on the market for strength, ease and flexibility of installation. Whether you are installing a classic Small Block, a V6 or a Generation III powerplant, we've got you covered.
Novak offers what we have found to be the most intelligent engine mounting system for Jeeps available, allowing the installer to make an easy and satisfying decision as to powertrain placement with the new engine, AX15 transmission and NP / NVG transfer case all considered.
Engine Cooling
For your GM engine, we will suggest the use of our RadLock high-performance conversion radiators, which are rugged, easy to install and are extremely efficient in cooling in even the most demanding environments.
Axles
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.