You have to buy the whole headlight motor assembly...and install metal gears yourself if you choose to (I just left the plastic one in since they last over 100K in my experience). You may be able to just fix the gear if it's doing the "popping" now or acting crazy if it's not completely dead. You don't have to replace in pairs.
1994 Firebird Formula "The Purple car" Plum Crazy Purple, 6spd, 383 LT1 and lots of suspension mods
1999 Firehawk Formula #37 "The Black car", Black, 6spd, longtubes, dyno tune. SLP options: level II suspension, Hurst shifter, Aurburn posi, SLP exhaust. More to come...
1966 Austin-Healey 3000 Mk III Blue/white two-tone. Toyota 5spd conversion, Proper British pimpmobile