Trans does not shift at redline
Lately I've noticed that when I have the pedal all the way down it shifts smoothly from 1st to 2nd, but from 2nd to 3rd it reaches 4800RPM and then bounces between 4600 and 4800. I let off the gas and the RPMs drop and it drives normally.
I have had no trans problems and service it regularly (fluid/filter). This doesn't happen every time I accelerate hard, only once in a while.
I know very little about automatic transmissions, so I'm in the dark.
Is the ZJ transmission vacuum controlled? Could I have a vacuum leak? Could this be a problem with the shift points or the bands (I don't really know what those are...).
Overall shifting is smooth, even under load or when towing.
I appreciate your time and help!