Right component supplies the sound: lù → lǜ, just a tone/rounding shift. The original phonetic was
彔 'water dripping from a pulley'; the simplified
录 keeps the same sound. As a phonetic it also drives
碌 lù (busy / pebble) and
禄 lù (official salary) — a tight lu/lǜ family sharing the same right-side shape.