The LVTP-7 was first introduced in 1972 as a replacement for the LVTP-5. In 1982, FMC was contracted to conduct the LVTP-7 Service Life Extension Program (SLEP), which converted the LVT-7 vehicles to the improved AAV-7A1 vehicle by adding an improved engine, transmission, and weapons system and improving the overall maintainability of the vehicle. The Cummins VT400 diesel engine replaced the GM 8V53T, and this was driven through FMC's HS-400-3A1 transmission. The hydraulic traverse and elevation of the weapon station was replaced by electric motors, which eliminated the danger from hydraulic fluid fires. The suspension and shock absorbers were strengthened as well. The fuel tank was made safer, and a fuel-burning smoke generator system was added. Eight smoke grenade launchers were also placed around the armament station. The headlight clusters were housed in a square recess instead of the earlier round type. The driver was provided with an improved instrument panel and a night vision device, and a new ventilation system was installed. These upgraded vehicles were originally called LVT-7A1, but the Marine Corps renamed the LVTP-7A1 to AAV-7A1 in 1984.