I have a 2001 Trans Am.
I had new rear axles and a 373 gear installed.
When I drive around 45-65 MPH sometimes all of a sudden the RPM's shoot up to 5,000 but the car seems to be holding or slightly losing acceleration. It does it more on hilly roads. When I get to the bottom of a hill and the car starts to accelerate is when it does it the most. It feels like I'm stomping on the gas with the car in neutral. To get it to stop I have to let off the gas. Sometimes I have to bring the car to a stop to get it to go away. It don't do it all the time. Just randomly. It did it one time and I just stomped on the gas and video tapped it. Well I burnt up the transmission. I took it to a tranny shop and had it rebuilt. It still did it so I bought all new sensors and a new internal wiring harness. No luck. He said he put a new torq converter when he rebuilt it. What sucks is everytime I take it to him it want do it.
If you have any ideas please help. All advice will be greatly appreciated.

Thanks in advance

 

Also my normal RPM around 65MPH is 2,000.
It does this when driving with the gas pedal or cruise.

 

The way you explained it seems like a bad converter issue to me.

 

Thanks. I was thinking that too. It just seems odd that it did it with my old converter and the new one. The shop is well respected and the guy told me he put a new TC in when he rebuilt it. I'm starting to think maybe he didn't.