It's difficult to determine antonyms for the colloquial phrase "keeps truckin'" because it can mean different things in different contexts. In general, the phrase implies persistence, resilience, or perseverance despite obstacles. Some possible antonyms could include giving up, surrendering, quitting, or faltering. These antonyms suggest a lack of determination or commitment to continue pursuing a goal. Alternatively, antonyms could include resting, slowing down, or taking a break. These antonyms suggest a willingness to pause or step back for self-care or reflection. Ultimately, the opposite of "keeps truckin'" depends on the specific situation and mindset of the person using the phrase.