I just bought a used 2010 malibu Ls with 67500 miles. I bought it with a trans leak that the original owner had no clue about, and i got it fixed right away. The vehicle runs great, accelerates and decelerates great, but i have noticed that when i try to maintain any speed seemingly under 45mph the car jerks. Not violently, it just shudders back and forth, if you will. When it does this the rpms bounce around between 1500 and 2 and if I give it some gas it stops, or if i let off the gas it stops. I have not noticed it does this when maintaining high speeds tho like on the freeway. Only when I'm cruising at a low constant speed under 45ish. Any ideas? Also, when i got the leak fixed i got news trans oil put in so its got the right amount of trans fluid. Thoughts?