He played guitar for Suicidal Tendencies in 1983, and ended up playing on their highly influential self titled debut. His guitar playing was highly influential for the developing Crossover Thrash scene during the early to mid 80s. As he blended Heavy Metal like solos into fast Hardcore Punk style guitar playing. The song "Institutionalized" was highly popular receiving countless airplays on radio and MTV, it was also featured in the 1984 cult movie "Repo Man", and was also recently featured in the movie "Iron Man" and several videos games like "Mat Hoffman's Pro BMX ", "Guitar Hero II" for PlayStation 2 and Xbox 360, and "Tony Hawk's American Wasteland". Estes ended up leaving Suicidal Tendencies before going on tour with them and was replaced by Jon Nelson.
He later joined a Heavy Metal band in 1984 called "Hostage" in which he played guitar. They played along the Sunset Strip in LA and gained some attention but the band folded after their lead singers drug problems was interfering with the band. Around the time with Hostage, Estes also collaborating in a side project with former Suicidal Tendencies band-mates Mike Muir and Lou Mayorga called "Los Cycos" and recorded one track "It's Not Easy" which ended up on the first "Welcome to Venice" compilation in 1985.
After the demise of Hostage, he formed "Gang of Love" in 1990 with Louchie Mayorga and heavy metal drummer for "Malice" Cliff Carruthers. The band mixed Hard Rock with Heavy Metal and were fortunate to have 3 different singers: "Jon Pierce", "Kid" (who sang briefly), and "Dante Marchi" thorough the bands life and recorded some high quality Demo's before calling it quits. Out of the ashes of Gang of Love, Estes resurrected the band with Dante and Cliff and changed the name of the band to "Skin on Skin" in 1993. SOS were able to receive extensive radio play in college's, especially their song "Reach for the sky" off their un-released "Skinned" album.
Grant Estes has kept a low-profile musically thorough the mid to late 90s and early 00s. In 2006 he joined up with former Suicidal Band-mates Louiche Mayorga, Amery Smith,and Daniel Clements from Excel,Kevin "The Jerk" Guercio from No Mercy in a project they call "AgainST" in which they played songs from Suicidal Tendencies 1st album in a few shows, and contributed 2 tracks for the newest "Welcome 2 Venice" compilation.