I have just started noticing this problem this summer. Last summer everything seemed normal. I have replaced both switches and done a fluid change about 3k ago. WHen the air is off, the tranny shifts smooth, only shifts hard when i am running the a/c. Any ideas what the issue could be?

 

check your battery and see if it is getting low on output

 

Maybe it's a belt issue. Will the dealer diagnose for free, or do they charge?

 

If they charge, call the Car Talk guys and see what they say. I'd be interested to know.

 

I do still have the original battery. Do you really think that could be the problem? I was going to replace it before winter time.

 

I believe that the compressor clutch is 40 amp so it is a draw on the system when engaged. that is why I asked. when my battery got near the end of it's life i noticed that my ac caused the car to run different than before. replaced battery and been good since.

 

ok thanks for the tip. im going to have it tested today and probably replace it. i'll let you know the outcome.