An ignition cable terminal assembly connects an ignition cable to a stud terminal of a spark plug. The assembly includes a metal sleeve that has a crimp barrel at an upper end, an intermediate compression ring, a lead-in below the compression ring and an inwardly directed stop ring below the lead-in. A lock sleeve inside the metal sleeve, has a plurality of spaced longitudinal channels in an inner cylindrical surface that communicate with an annular cavity at an upper end. The longitudinal channels include lock channels that have lock ledges at the cavity and release channels between the lock channels. Upper and lower ring gears are inside the lock sleeve. The lower ring gear engages the top of the stud terminal and has radial teeth that slide in the channels of the lock sleeve. The lower ring gear also carries a plurality of circumferentially spaced, cantilevered, spring contact arms that extend below the bottom of the lower ring gear for establishing an electrical connection between the metal sleeve and the stud terminal of the spark plug. The upper ring gear has radial teeth that slide in the release channels and index into engagement with the lock ledges to lock the terminal assembly to the spark plug. The upper ring gear has ramps engaging ramps of the lower ring gear for indexing. A spring biases the upper and lower ring gears downwardly. The ring gears recede into the lock sleeve and index the upper ring gear into engagement with the lock ledges to lock the spring contact arms into tight engagement with the stud terminal when the ignition cable assembly is pushed down onto the stud terminal.