Tone Loc -- Accused of Being a Deadbeat Dad

Tone Loc works all week, 9 to 5 for his money ... but his baby mama claims he doesn't give her any of it and owes her thousands of dollars in back child support, TMZ has learned.

According to court docs filed by Eilise Sharkey, Tone has fallen behind on payments to her to the tune of $40,512. Sharkey points to a child support order that came down last October, ordering him to pay $3,376/month for their son.

Sharkey claims Tone should have no problem getting the money, saying he gets $5,000 per show and "he has several shows monthly."

Sharkey and Loc have a heated history -- he pled no contest to spousal abuse not long before the child support order came down.