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.
Sorry for the confusion. Mine has never shifted at the redline - it get's close to 5000, around 4800, and shifts. Lately, it's been hitting 4800 and bouncing between 4600 and 4800 until I let off the throttle. It's like there isn't enough of a "signal" to shift, whether it's TV cable related or pressure related. I'll look at the TV cable. I found a couple of writeups. Any specific recommendations?