KoRn -- Ex Drummer Sues Band ... You Shucked Me!

David Silveria took a temporary break from drumming for KoRn -- and when he tried to rejoin the metal band, they turned him away ... so now he's suing.

According to the docs ... Silveria says his leave in 2006 was merely a hiatus, and he never gave up his ownership interest in KoRn. So, even though he wasn't jamming with 'em, he was still sharing the profits.

Silveria says when he was ready for his triumphant return in 2013, the other KoRn members -- Jonathan Davis, James Shaffer, Brian Welch, and Reggie Arvizu -- told him to kick rocks.

Silveria feels especially slighted because he claims Welch had taken a leave of absence, and was welcomed back with open arms.

Now, he's asking a judge to force the band to reveal how much cash they've made since he left -- so he can get his cut -- and then he wants to dissolve the partnership.