Transmission shifting hard

PONTIACG6JEAN

MEMBER
2008 PONTIAC G6
V6
4WD
AUTOMATIC
150,000 MILES

It shifts hard almost jerking into gear when accelerating from first to second or second to third. I took it to a transmission shop and it didn’t read any codes. They did a service on it and it’s still shifting the same. The guys that drove it at the shop said they didn’t notice it shifting hard but I don’t understand how they didn’t feel it. They also said these cars have something electrical that cause it to do that and it’s normal? I’m confused. I’m told everything else is good. Should I try to change the spark plugs? Could it be something else that I haven’t checked? Thank you.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi,

Since there are no codes, that makes it a bit tougher. A hard shift can be caused by a couple of different things. For example, high line pressure can cause it. However, that should set a code.

Since they told you there are no codes, there is one other component that can be an issue, the transmission fluid temperature sensor. Interestingly, if the sensor is sending a signal (right or wrong) the computer is receiving a signal and doesn't realize something is wrong.

Do this for me, The sensor is in the transmission and requires the pan to be removed. So, contact the shop that did the work and ask them if the sensor was checked. If they say there were no codes for it, ask if they can check if it is sending an accurate signal.

If that is good, then ask if they checked line pressure to make sure there isn't an issue with high pressure.

Let me know what you find.

Joe