Checking fluid level

I feel so stupid. I went to a mechanic because I need a fuel pump replaced very soon. My youngest son said to get a transmission fluid changed. I have never had this done before. Will it hurt the engine or car in general to change it now?
I feel so stupid about this. Please advise. I have had regular oil changes with synthetic oil, and checked all the fluids except transmission fluid obviously.

How often do I need to change the transmission fluid?

When should I do a transmission fluid flush?

I have a 2006 chevy Malibu and my mileage is roughly 101,700. I have been told that it should roughly be done at 90,000 by my dealership and another mechanic said it could go to 100,000. With a tight budget I still need to new back tires (already have 2 new ones in front). First, when should a transmission flush be done typically on a 2006 chevy malibu (car appears to be running just fine) and second what should I do first the tranny service or get the 2 new tires? Thanks

Transmission problem
2004 Chevy Malibu 4 cyl Front Wheel Drive

I would really appreciate if you can guide me on how to do transmission oil change with filter on a 2004 Chevy Malibu, 2.2L, 4Cyl.

My wife's car is a 2006 Chevy Malibu Maxx. We bought the car a year ago as a beater to get her back and forth to work, about 8 miles a day. It currently has 188k miles on it and I would like to see it hit 200k before I scrap it, but I am not willing to put a bunch of money into it so I would like some constructive advice.

I am a computer repair guy with enough auto repair knowledge to make a real mechanic mad, so feel free to bash me for my obstinance and bad decisions before providing your constructive advice. I have included a lot of detail because I don't know what will strike a chord.

This adventure started when the car began lurching every once in awhile while accelerating. Not very much, but just enough to notice. Felt like the transmission slipping a little to me. It was also shifting a little hard into reverse and drive when sitting still. It has no dipstick. Sealed, dealer service, all that jazz. I will not go into my thoughts on that. So, I did my online research and found out that there is a sight hole on the tranny. Everything I read said that you make sure the car is running, at operating temperature, and level and add fluid until it starts coming out the sight hole. OK, sounds simple enough. I planned to top it off with LG Red, drive it for a week, then drop the pan, change the filter and refill it with new fluid.

I have a nice level spot where I can pull up over a depression and slide under the car. I ran it to operating temperature, shifted through the gears slowly several times, and crawled under with my trusty drain pan. I started loosening the sight plug and fluid started dribbling out. I figured someone had added an extra quart sometime, so I let it dribble... and dribble... and dribble.

After two quarts, I went back to the computer and reread all of the information I had found, thinking I had missed something. Again, everything indicated adding fluid until it comes out the sight hole, indicating that it is full. (All the web pages and diagrams are listed below.)

Back under the car, I kept draining. I ended up with over 6 quarts of fluid. OK, I am questioning everything now, but figuring somebody just overfilled it since there is no dipstick and information is so hard to find. I shifted through the gears, and it was smooth as glass (not good as you will see). I put it in reverse and backed up a few yards, then pulled forward. It seemed sluggish. Back and forth just a few yards several times. About the fourth attempt to pull forward, it would not move. Engine revs, no pull. Well, obviously that amount of fluid was necessary. Not having planned well apparently, I did not have 6 quarts of new fluid and the wife took my truck to work while I worked on this. I added the quart of LG Red and the one new quart I had on hand, then used coffee filters to filter the old fluid before adding it back in. It is dark, but still red and no funny smell. (Drain pan was new and clean, so no weird contaminants.)

It started pulling again, thank God. I drove it slowly around the block a couple times, but it keeps dropping into limp mode. I have a BT OBDII scanner. The output is included below. (Ignore the P0401. That is for a different day.)

QUESTIONS:
1) What am I doing wrong on the fluid level check? I followed all instructions and when I get the level at the sight hole the car stops moving. (Photo of sight hole included just in case I am opening the wrong one.)
2) Is the P0756 something I damaged in this process, or possibly the original problem?
3) Why are there 6 quarts of fluid ABOVE the sight hole?

https://www.2carpros.com/questions/chevrolet-malibu-1997-chevy-malibu-checking-fluid

Thanks hmac300.

Yes, I was opening the wrong hole (smacks head on wall). The one I circled IS an 11mm plug, not a line, so I don't feel completely stupid, I was just not far enough back under the car. Rookie mistake, I know. I found the other one and will be much more attentive in the future. Still had to remove a little over 2 quarts, so with all of the draining, filtering and refilling I still think there was at least one quart too much.

I will be spending Mother's Day under her car trying to resolve the remaining issue, which is the "P0756 Shift Solenoid "B" Performance or Stuck Off" error. I think that was probably the original problem, although it was not throwing a code yet. Fluid is dark, but still fairly red, not dark brown or black.

Thanks for the advice on the other codes. Those have been on my to do list for a few weeks, just have not had time.