Auto trans. question

[C_Dogg]

Six months ago I upgraded from a '97 to an '01. Both are automatics. The new one seems to shift earlier and then labor. I've just returned from Nashville, and noticed that especially at 1500 rpm (60mph) it is greatly exagerated. It produces a very loud exhaust vibration that drowns out the radio.
My guess is, that the trans is shifting too soon at slow speeds, and not gearing down at higher speeds. What tells the trans to shift? Can this be fixed by adjusting the computer? The car is still under warranty, but I don't have a competant dealer in the area that I can trust. I guess I need some good advice.
Tnx in advance,
Stan :confused

 

[c4c5specialist]

Hi there,
Unfortunately, there is so much technically going on with your automatic transmission, that I could not possibly address all aspects of this here.
First, just be aware, your 97 had a totally different computer program for the automatic transmission controls than the 01 that you have now. Your 01 has 350 horsepower, where your 97 had 345. This may seem like a small difference, however, it is just the tip of the iceburg.
A simple description is that your transmission will compensate for internal wear, and driving style. The ideal shift time for a basic part throttle shift, under 50% is about .20-.40 seconds.
Now, if there is nothing that needs changing, the transmission does NOT adjust the pressures and shift times to compensate. However, if the PCM sees that the pressures and shift times are unacceptable, things are changed to make the shift acceptable per PCM guidelines.
So, if you are having a shifting issue, the first thing to do is make sure that your TAPS, or transmission adaptive program settings are reset to new.
Next, a check for the latest PCM updated calibrations is also in order.
MANY THINGS CONTROL TRANSMISSION SHIFT POINTS. I am only touching on the simplest things that you can explain to your dealership, so that they may serve you well.
There may be other issues here, but always go for the easiest repair first, and then reevaluate the situation.
Allthebest, c4c5

 

[C_Dogg]

Thanks for the info. I was not aware that there was a difference between the two cars. The bottom line is... something has to be done! Thanks again, I really appreciate your input. ;worship