My wife's 2003 impala has started hucking and bucking every once in a while. Most often it is when we are accelerating after making a turn, but not always. I have caught it a couple of times and thrown it into neutral and the shaking stops. Is this my transmission? Any suggestions?

Have you checked for crawdads in the gearbox?

Auto or manual?

 

Can you describe the "hucking and bucking" furhter?

They are only offered in auto

Sounds like it may be a tune up issue but them engines are known for sucking the intake gasket it's a easy fix but ever chevy 3200,3400,3600 series engine does it at some point.

Is the vehicle at full operating temp when this happens or ? Also is the check engine light on ? Is the check engine light flashing when it starts acting up ? If you have a trouble code we can go further , if the check engine light is flashing this is a sign of a cylinder misfire . If no codes or no lights are present then this may be possible signs of a weak or dying ignition coil . However also can be other possible issues . Once I have some more info I can assit you further .