Formed in summer of 2003, Clockcleaner released an LP called The Hassler on the now defunct Philadelphia label Manic Ride Records. The album echoed early 90s noise rock, with high pitch guitar sonics and a thumping bass sound. After touring for the EP original bassist R. Slegel left the band, and was replaced in the studio by John Sharkey. In Early 2006 they released a 7" on Baltimore’s Noise/Avant label Hit-Dat Records (Missing Dick b/w Crucifucks' cover By the Door). Soon to follow was their second LP, released on another Baltimore label, Reptilian Records. The album was called Nevermind (a sarcastic ode to Nirvana’s 1991 release). The record was allegedly recorded while Sharkey was under a state of bi-lateral amnesia from a car accident in summer of 2005. John Sharkey has insisted that the title was a joke to piss people off (He has even gone as far to call Nirvana "dogshit" in a Dusted Magazine interview in 2007).
"People think that record is like the Bible," says Sharkey via phone from his North Philadelphia home. "Fuck that record. It's completely piss-poor. It did not stand the test of time. I can understand the mania that it caused, and I mean, it's good because hair metal sucked, but it almost caused another fuckin' trend that I have no concept of at all – alternative or modern rock. So, Nirvana were dogshit, and I thought it was funny to name our record Nevermind. I kind of wanted people to react like, 'What balls! Who the fuck are these assholes?'"
"Nevermind" was a departure from their punk sound. Nevermind had more in common with many of the mid to late 90s Siltbreeze bands such as Harry Pussy and The Dead C. After the album was recorded Karen Horner became the permanent bassist. Her first show with Clockcleaner was opening for The Melvins. The album did well with many critics and in late 2006 the group signed to Load Records. Babylon Rules followed for the label.
The band toured extensively during the fall of 2007 in support of Babylon Rules in the US playing mainly with acts championed by the band, such as Mika Miko, The Lamps and The Homostupids.