2004 Matrix transmission

If the ATF is truly getting noticeably dirtier by the month, then either you are doing a lot of driving each month or the transmission is slipping. I am not saying you are doing this, but I see a lot of people shift from forward to reverse and vice versa before the vehicle is completely stopped, and that puts a lot of wear and tear on the transmission, especially when maneuvering in a tight space. Stop-and-go driving, towing, and driving with stuff on the roof rack will also put more wear and tear on an automatic transmission. A competent technician can check whether the transmission is slipping with a stall test and by checking transmission line pressures.

You can probably order T-IV from one of the dealers that sell parts online or you can purchase it over the counter at a dealer and then bring it wherever you have your vehicle serviced to have the fluid changed.

This is a grocery getter... ( My wifes car). 20 miles a day and occasional trip to see mama. Nothing being overdone here I determined the condition by looking at the fluid wipe on a paper towel. It doesn't look pink ( whether or not it was at the start, I don't know), but doesn't smell burned either. There's a slight dark grey deposit when you wipe the dipstick off.

I have learned over the years that wives do not appreciate any mechanical problems or failures, whether they are self-inflicted or not. For example, my wife was complaining that the garage door panel makes a loud popping noise when going up and down, even though we had the garage doors replaced only a month before. I pointed out that the cause of the popping noise was where she had hit the garage door when it was a week old and dented 2 panels, and the panels were binding because they were caved in.

Regarding the ATF, it sounds like the car is not running under any severe operating conditions, and the color does not sound that bad. If were looking for some peace of mind, then I would change the ATF at 60,000 miles.