Hard shifting problem

[JustinOhio]

Hello all, I've been browsing this forum for a while, good information here :) I have a question..

2000 Firebird, 3.8 auto, 92k miles......

After driving my car for over 20 miles on the highway I'll start to hear a slight winding noise coming from somewhere, I can't tell exactly where (possibly transmission), and during this period the car will shift hard into each gear. It acts exactly as it would if a shift kit were installed. The tires even break loose a little during the 1-2 and 2-3 shift if I give it half throttle or so.

To remedy the situation, all I have to do is stop the car, put it in park, shut the key completely off, then restart and the problem will go away (winding noise too) until the next time I happen to drive a little distance on the highway. I could drive for 40 or 50 miles in town and it won't enter this hard shifting and winding noise mode, it only happens after being on the highway doing 60 or so.

I've done some searches on the forum but I haven't been able to come up with anything. Any suggestions?

[usp55]

Re: Hard shifting problem

could it be your rear?

[JustinOhio]

Re: Hard shifting problem

But would shutting the car off and back on be something that would solve that? I was thinking it was something with a sensor somewhere, since resetting the computer basically solves the problem.

[Mr.Britt]

Re: Hard shifting problem

I have the same problem with my 97 camaro rs, it only happens when i get on the highway also, i can drive around town all day with no problem.But in my case i have to let my car sit for a couple of minutes then its back to normal...I was searching the post for the same answer....But i did do a transmission tune up( fluid and screen) and that helped for about a week or 2, but back to the same problem now.

[bigbrian442]

Re: Hard shifting problem

Scan the PCM for codes. Some codes setting will cause the PCM to peg the Trans pressures and cause this. You may have to scan it while it is doing this, although OBDII should store the code.

[pace2006]

Re: Hard shifting problem

P1870 code will probably show up. Common problem with the 4L60E. Search and read in some of the more recent threads about this code. They explain how to fix it.

[Everglades W68]

Re: Hard shifting problem

The original poster gives a good description of the P1870 problem.

The inexpensive part below fixes this problem. I've seen a lot of posts with this same problem described, so maybe this will help the next persons who come here looking for the answer.