If the battery was recently disconnected, expect unusual shifting until the computer relearns how much fluid volume it takes to apply each clutch. That relearn procedure usually takes less than a few miles of driving after it's warmed up.
If it has always been doing these things, ask your dealer if there is a "flash" or updated software they can install to address these issues. Delayed downshift when stopping is called "bump shift" and is rather common. It's designed to reduce unnecessary downshifting when just coasting at a very low speed. My '93 Dynasty does that too. It was flashed for the bump shift problem right after I bought but it didn't make any difference. The car only has 3600 miles. I just put 200 miles on it this summer, and I still notice the bump shift, but other up and downshifts are so smooth and unnoticeable, I'm not going to monkey with it.
When you say it seems to shift hard into second gear, do you mean upshifting or downshifting into second? Downshifting hard can be related to bump shift. Upshifting hard can be caused by letting off the gas pedal a little just as the shift is about to occur. Speed and throttle position work together to set the shift speed and harshness. Once the computer decides how hard to apply the clutches, reducing load on the transmission will make the shift more harsh than intended.
Use of the wrong transmission fluid will introduce a bunch of problems. Most noticeable is a chatter or shudder as the clutches apply. The proper fluid delivers the designed amount of friction between the clutch plates.
Have you noticed the clicking, or ratcheting sound from the transmission when you shift into drive or reverse, and when you come to a stop? That is done to soften the feel of clutch engagement. Fluid with the wrong additives affect this feel.
Friday, August 28th, 2009 AT 5:57 PM