Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hello my name is***** am an ASE Master Technician and I am glad to help you out with your question.
Scan for codes and let me know what you find. A common problem is a line pressure code in the trans which will cause a hard shift when the trans is warm.
This will usually set a p1811 code.
Another common trans problem is the 4th gear clutch hub stripping out. Which will cause a long shift and will set the code. This code creates max line pressure in transmission, that is why it will shift hard.
I had a grand prix that did the same thing and I drove it that way for years.
Please reply to this if you need more help and we can continue this conversation. If you are satisfied with my service, please rate at the top of the screen. Rating does not close out your question. Remember, sometimes it is difficult to completely diagnose your vehicle without being there, but I will try to give you the best answer I can. If I am not giving you 5 star service, please let me know what I missed.
ASE Master Technician