OK, so I have a 92 SE - Auto tranny. My tranny has been shifting very badly lately. Like, I wont push on the gas very hard and it will still go way up on the tach before it shifted, and sometimes just redline unless I let off the gas completely. So, I had gotten used to this taking it as my tranny going bad. But the other day, it started shifting perfectly, 3K RPM area shifts with normal pedal movement. The only thing I had done differently was speeding on the interstate. I caught myself going over 100 and backed off. Thats the only thing I can imagine I did differently. So what do you guys think? What happened?

 

You probably had some frictional material stuck in a valve. Somehow or another it has freed itself. The first thing you should now do is change your tranny fluid. I have had this happen before also on my '91 Sentra.

 

Yeah, def problem in valve body - happened to my roomie's nx auto & I changed the valve body - along with oil & filter. Problem solved.
I currently have similar problem only with 2-3 upshift. I can live with it - for now. Maybe I should try speeding at 100 as well!