The 700R4 is a four-speed automatic transmission developed by General Motors. Known for its overdrive gear, this transmission offers improved fuel economy at highway speeds compared to earlier three-speed automatics. Adapting this transmission to a four-wheel-drive system requires a specific transfer case and appropriate driveshafts. This setup was commonly found in various GM trucks and SUVs from the mid-1980s through the mid-1990s. A typical application might include a Chevrolet K1500 pickup truck equipped with both the transmission and a New Process 208 transfer case.
The combination of this four-speed automatic with four-wheel drive provided a significant advancement in both on- and off-road capability. The overdrive gear reduced engine RPM at higher speeds, leading to better fuel efficiency. Furthermore, the four forward gears offered more precise gear selection for various driving conditions, including towing and low-speed off-road maneuvering. This made vehicles so equipped more versatile and desirable for a wider range of uses compared to vehicles with older three-speed automatic or manual transmissions. Its introduction marked a shift toward more refined and fuel-efficient four-wheel-drive systems.