GM Genuine Parts 87840007 Power Liftgate Actuator Assembly

The GM Genuine Parts 87840007 is a left-hand (driver side) rear power liftgate actuator assembly designed as a direct OEM replacement for the liftgate power assist system. It integrates a 12V DC electric motor, a worm gear drive mechanism, and a coiled torsion spring within a sealed housing to provide assisted opening and closing force for the rear liftgate. The unit features an integrated position sensor and control circuitry communicating via the vehicle LIN bus or discrete signaling for anti-pinch protection and position memory. The housing is constructed from high-strength engineered thermoplastic with stainless steel mounting brackets and a corrosion-resistant coated steel cylinder rod. The electrical connector is a sealed weather-pack interface compatible with the vehicle body harness. This actuator supersedes previous design iterations including OE numbers 84806679 and 86594923, incorporating updated internal gear materials and seal geometry for improved low-temperature operation and cycle life durability. Installation requires no programming; the module self-calibrates on first power-up cycle.