Chevrolet Repair Questions? Ask a 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.
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