So I've been thinkin about taking a road trip thats about 8-9 hours...problem is after driving for somewhat of a long period of time (maybe 30-45 minutes) my trans starts to shift hard. You guys think it'll be ok for this long trip?

 

Is the trans throwing any codes? Does it still hard shift after you restart the car?

 

tripleedgeperformance.com has a great read on your transmission

 

I drove my '99 Chevy Venture minivan for years after it started doing this. It was the 3.4 though. If it started to shift hard, I would pull over turn it off, restart the engine and it went away. I forget what the exact code was. I was told the PCM turned up the line pressure "to protect itself." Never did find out what it was protecting itself from. It still ran great (other than this occasional issue) when I traded it in. Maybe this is a similar issue.
I never fixed it because everyone wanted to rebuild or replace the tranny. I figured I would grenade the tranny completely first, if this was the case.

 

Haven't taken it in to see if its throwing any codes but the read-up on tripleedgeperformance about the P1811 seems to be the exact problem. It'll go away after I turn the car off for a couple minutes and restart. Well I have another year of warranty left so Ill just drive it and see what happens lol...thanks for the info guys.

 

My Monte does the same thing. It does not set a code. The trans has been doing this shifting since I got it back in may 2010. Best to be careful and watch or feel for drastic changes. Monitor the fluid and check level frequently. If the fluid needs service change and replace filter

 

Your problem could also be a bad cat, and when it gets hot starts to mess with you

 

My van didn't throw the code every time either. I wish I had tracked down the problem.

 

x2 but if its a long trip you will probably be cruising in cruise control so youd be fine

 

I would lean more towards PCS in the trans (Pressure Control Solenoid). They tend to go out in these trans. Does it up shift hard, over rev and then almost slam into gear? I would bet it doesn't do it all the time just intermittently. Also if you park your car lets say for 30 min and then drive it again and it doesn't happen again, I would say its the PCS.