I have an automatic Saturn not sure the year, but it jerks hard when it is...

[cestevespr]

...shifting gears.? When the car gets up in rpms it jerks as it is trying to shift gears. Now the car wont start at all. Before all this heppened though i noticed the car was running a little louder then normal and was shaky (if that makes sense).

 

[DE1]

Is the "Check engine light" on? Many times when there is a problem with the engine management system (OBD2) the car will go into "Limp" mode to compensate for what ever sensor or other part that is failing. When in limp mode, the transmission will shift into a default mode which can be notices by hard shifting. If that isn't the problem, I would check the fluid when the car is running and in Park to see if it is low.

Hope that helps

 

[Gurk]

motor mounts, probably the tranmission motor mount

 

[Clayton]

check to make sure the transmission has fluid in it