I've got a 96 RS camaro 3.8 with auto trans. last sunday i was driving home and i noticed it started shifting hard into 4th. monday going to work the same thing was happening. on the way home it started jumping from 3rd to 4th repeatedly around 40-45mph. tuesday through today hasnt jumped gears but still shifts hard into 4th. any ideas?!?! i havent had any problems with it prior to sunday. and also when im cruising highway speeds 65-70mph the rpms are about 2,500 so i'm thinking i lost overdrive. i dont ever remember the rpms being so high at cruising speeds. any ideas please!

 

or is 4th gear overdrive?

 

4th gear is overdrive, 3rd gear is direct drive, 1st & 2nd gear are underdrives.

 

I think you are having solinoide problems. Normally it's just reverse that goes when your tranny goes. But bad solenoids will cause jerky shifting or high revving before shifting.

 

What? Reverse requires the highest line pressure to work but it is pretty rare for a car to show up with no reverse and forward still working.

The most common issue that will cause hard shifting is a sticking accumulator or a broken accumulator spring.