well i did have the car custom tuned and the firmness bumped up a little about 3000 miles ago.. i noticed POT it was a good bit harder but not untolerable.. if you ease on the gas it wouldnt shift that hard, but on the way home tonight i noticed that no mattr how u drive, very easy, a little on it or wot it shifts really hard...... it does it to where its very noticable in 1-2 and 2-3 3-4 feels like its been....... i dont feel any sliping at all? i just been driving the car for a couple months and i felt a big difference tonight... is it time for a trans or do you think its something else? i am not a trans man so i would apreciate all the info i can get.......... thanks yall

 

If you only notice it on one particular shift, and it happened all of the sudden, it may be a problem with the 1-2 accumulator. It could be something as simple as the spring breaking. The accumulator is located behind the valve body, and is only held on by (3) 10MM bolts, so it's pretty easy to check.
If ALL shifts, as well as the initial engagements got firmer, I'd say look toward the Pressure Control Solenoid (EPC).

Frank
CPT

 

Scan it for trouble codes. Some transmission codes result in harsh shifting because of an increase in line pressure. Also, some transmission codes do not cause the SES to come on.