[quote author=jdrake4 link=topic=143181.msg3084939#msg3084939 date=1240753817]
2005 Mazda3 2.3L 53,000 miles.
About 2,000 miles ago i did an automatic transmission flush myself using the directions on this site, by disconnecting the trans cooler draining 3 quarts refill etc....
I used Mobil 1 synthetic for the flush.
Car drove great afterward.
I just drove the car yesterday and noticed car does not want to shift from 1st to 2nd when the car is cold. when it does make the shift it is a very hard shift. It also does it from 2nd to third but no where near as bad.
My wife said this started about 1 month ago, which is when I flushed the fluid.
I can tell you that if this is the FIRST transmission fluid change, and you waited until 51K miles to do a fluid change, the trans is dying.
The auto's eat up the trans fluid really bad, especially if it is conventional. Even at 12K, many report the trans fluid to be very dark and filled with clutch material.
Trans fluid has aggressive cleaning agents in it. If the trans is going bad, a fluid change will actually accelerate the failure.
The first thing I did on my AUTO was to change the trans fluid at 2K miles. I used synthetic. I will do another change at 5K.
If I were you, and the cars under the powertrain warranty. Go to the Mazda dealer and get it checked out. If the warranty is done, all you can do is keep an eye on it. Make sure the LEVEL is good. Low trans fluid can give you erratic shifts also.