A shock absorber for a vehicle suspension includes a pneumatic actuator that is fluidly connected to a compressed air source in the vehicle suspension, such as a suspension air bag. The pneumatic actuator cooperates with an adjustment mechanism housed within the shock absorber to adjust damping. The shock absorber includes a main rod that supports a piston for axial movement within a cylinder body. The piston separates the cylinder body into first and second fluid chambers. The adjustment mechanism includes an adjustment rod that is received within an axial bore formed within the main rod. The adjustment rod is axially moved within the axial bore by the pneumatic actuator to uncover and cover a plurality of bores that are in fluid communication with at least one of the first and second fluid chambers. The pneumatic actuator includes a plunger having a tapered surface that engages the adjuster rod to move the adjuster rod in a desired direction to adjust damping. A fitting and a restrictor plug cooperate to fluidly connect the pneumatic actuator to the compressed air source and to meter air flow to attenuate pressure spikes.