The Novak Guides to Automatic Transmissions in Jeeps

The TH400 is the Big Daddy of the GM automatics. Brutally tough, relatively efficient and totally buildable

• Compatibile with classic and modern GM engines, as well as AMC I6 & V8 engines
• Self-shifting hydraulic control
• Aluminum alloy case with integral bellhousing
• Strong and smooth operating in both street and off-road environments
• Adaptable to essentially all of the Jeep transfer cases
• Found in some 1964-1995+ GM vehicles

The 700R4 is the great result of what happens when a company like GM doggedly sticks with it. It was released with its share of bugs, but it didn't stay that was for long. It's a top choice in some of the best Jeep upgrades out there

• Compatibile with classic and modern GM engines
• Either hydraulically (700R4 / 4L60) or electronically operated (4L60E) transmission
• Aluminum alloy case with integral bellhousing
• Very durable, geared well and smooth operating in both street and off-road environments
• Adaptable to essentially all of the Jeep transfer cases
• Found in some 1982-1996 GM vehicles

The 4L60E (and similar 4L65 & 4L70) presents the culminated engineering greatness of five decades of GM automatic power transmission design and is the dominant conversion transmission of this era

• Compatibility with modern GM engines
• An electronically operated transmission that is controlled by the integrated Powertrain Management Computer
• Aluminum alloy case with non-integral bellhousing
• Very durable, geared well and smooth operating in both street and off-road environments
• Adaptable to essentially all of the Jeep transfer cases
• Found in some 1997-present GM vehicles

The 4L80E (and similar 4L85) descended directly from the TH400, and improved on it with overdrive and a lockup torque converter

• Compatibility with modern GM engines
• An electronically operated transmission that is controlled by the integrated Powertrain Management Computer
• Aluminum alloy case with non-integral bellhousing
• Impressively durable, geared well and smooth operating in both street and off-road environments
• Adaptable to most of the Jeep transfer cases from 1980-present
• Found in some 1991-present GM vehicles

The 6L80 and similar 6L90 are GM's newest and most revolutionary transmissions. Though not yet ready for full acceptance in conversions like the famous 4L60E, they are steadily rising

• Six forward speeds
• Compatibility with Gen IV GM engines
• An electronically operated transmission that is controlled by the networking of a GM Gen IV ECM and integrated TCM
• Aluminum alloy case with non-integral bellhousing
• Highly durable, geared very well and smooth operating in both street and off-road environments
• Adaptable to most Jeep transfer cases, 1980-present
• Found in some 2007-present GM vehicles

The AW4 transmission was a step into the modern era for Jeep, with its overdrive and electronic control

• Compatibile with AMC I6 engines
• Electronic control, via its own computer (when interfaced with an ECM) or an integrated PCM
• Aluminum alloy case with non-integral bellhousing
• Moderate strength
• Found in the 1987-2001 Jeep XJ

The 727 transmission was the strongest automatic transmission option post-1979 in Jeeps

• Jeep version compatibe with AMC V8 engines
• Very strong
• Aluminum alloy case with integral
• Does not fit well into CJ's
• Found in the 1980-1991 Jeep FSJ models