clearance issues with the frictions and steels in the clutch packs or a line pressure solenoid failing, or PCM issues, low fluid will not cause hard shifts, it would cause slippage and no movement, take it to a trans shop
It could be shifting hard because you are low on transmission fluid. Just pop the hood and check to see what your fluid level is at. If you add fluid make sure your car is running and the engine is warmed up.
Traditionally when transmissions shift hard, there is a major internal issue with your transmission. You should have a local transmission shop properly diagnose your transmission. It could be the transmission is going out. Perhaps your low or out of transmission fluid also.
If your Chevy Malibu transmission is an automatic transmission, then the reason it is shifting hard is possibly because you need to add some transmission fluid. If it is a manual transmission, it may need some grease to be added to the transmission.
