Primus Drummer Quits Band Via Email

Primus is in the market for a new drummer ... because Tim Alexander abruptly quit the hard rock group ... informing his bandmates via electronic communications.

The band announced Tuesday that Tim quit Primus "effective immediately" ... after firing off an email to founding members Les Claypool and Larry LaLonde.

Primus says they were blindsided when Tim decided to quit ... and, the band says he went radio silent after dropping out, aside from one response where he told them he had "lost his passion for playing."

Tim joined Primus way back in 1989 ... though he took a 7-year hiatus in 1996 before returning.

The band's biggest hit was the 1993 classic "My Name is Mud" ... and Primus recorded the OG theme song for "South Park."

Les and Larry say they're disappointed to lose Tim but they respect his choice ... and, the band says it's still planning to take the stage Dec. 31 for a New Year's Eve gig at the Fox Theater in Oakland, without Tim of course.

Tim had open heart surgery back in 2014 ... but it doesn't sound like health is a factor in his departure.