I believe they all have a drain plug and that the filter is only serviceable if the transmission is removed.
The key is measuring the amount that comes out and replacing that amount. This holds true if the level is correct prior to draining. Not sure on the older ones but the 12’+ yields about 4-4.5 qts.
I did it several times driving some miles between.

 

Just do several fluid drain and fills. Drain it, drive around for 10-20 miles and drain and fill again. FLUID is cheaper than parts! If it was real dirty, do it again next oil change.

 

2010 has the older 4 speed trans, the 4T65E. There is not a drain plug. The filter is serviceable and is easy to do with the pan off. The bottom pan are dropped for both fluid and filter.

 

Is there a recommended brand of filter? GM OEM?

 

I use AC Delco TF304. < $20 at RockAuto. The OE pan gasket is reusable many times.

 

I use oem for just about everything.

 

There are different trains of thought on replacing the fluid in a transmission with that many miles. Some say don't. Some say to drop the pan, change the filter and reuse the old fluid. However, if the fluid is dark and dirty, most will not reuse it. The reason is the old fluid has grit in it from wear and helps with friction between the clutches and steels. If you introduce new fluid, your transmission could start slipping. Not saying that will happen. Most pros will tell you to either change your fluid and filter every 25-30k miles or don't change it at all. It may help your transmission shift better however. I would never recommend a flush though. Flushing can cause serious issues on worn transmissions. Bottom line, if your fluid is burnt and really dark, you probably should change it with the understanding there will be several quarts remaining in the torque converter. It would probably take two or three changes within a few hours of each other to remove most of the old fluid.

 

I used to do trans overhauls at dealership....my experience was most failures were from dirty fluid [new ones were from split seals]. Keep the fluid clean.

 

When I did my 2011 LT trans which is the last year of the 4 speed auto, I purchased from Advanced Auto a new trans pan that has the drain plug made into it. I reused the old gasket.

 

I had an 08 LT with 168,000 miles and what I did was a sort of flush last summer. Ramps help with this, but jack and jack stands will also work. I used a WIX filter from AutoZone and Valvoline High Mileage ATF that's DEX IV approved. I disconnected and hooked the transmission line from the radiator to a hose and put the other end of the hose in a catch pan. Started it, let it run the old fluid out until it just about started to bubble. Anywhere from 4 - 6 quarts came out. I then poured in a jug of Dex IV trans fluid and repeated the process a second time. Most (not all) of the old stuff came out. I then added another jug and ran it a third time until the fluid coming out looked brand new. I then dropped the pan, cleaned it, removed and replaced the filter (didn't change the seal as it was still sealing) replaced the gasket and reinstalled the pan. Filled it with almost 2 gallon jugs of Dex IV. Reconnected the line back onto the transmission and started it up. Let it run until it reached operating temp and checked the level. Topped off as needed and drove it on my 50 mile round trip commute to work and back. At the end of each drive, I checked the level and added fluid as needed. Shifts were firm and there was no sputtering, slippage or any other issues that some may encounter during a flush. Ran like a top until I was in an accident the week of Thanksgiving. Now I have an 02 Trailblazer LTZ and am about to do this same flush on it as well. Only real difference is the Trailblazer has 96000 miles on it.

 

Those are helpful replies. Just to clarify, I am not noticing issues with shifts currently, but do plan to change fluid without a flush, possibly a pseudo flush as metalmike187 suggested, and likely replacing the filter.

 

One thing I should have noted before is that the filters on these things aren't filters in the traditional sense, but more a catch medium. It's almost like a folded in half pad that's put in the plastic and is intended to trap the larger particles. If you're dropping the pan and removing fluid, do the filter. Then cut open the old one and look at what's in there.

 

That seems like a great way to get as much fluid as possible.

 

With this method, you get about 90% of the fluid. The bit in the torque converter doesn't go because you aren't driving and the bit in the cooler in the radiator doesn't go either. It's a negligible amount and anything in it will be caught in the new filter.

 

If you have the time, put the car on ramps and let it sit for a few days. The reason is fluid will drain out of the torque convertor as it sits. I recently did a fluid change on a 4T65E-HD and it took almost 8 quarts of fluid to re-fill.

If you replace the filter seal on a 4T65 be aware it is a minor PITA to get out. There are a few videos out there on tips and tricks for it, but it is something to note.

 

If you replace the filter seal on a 4T65 be aware it is a minor PITA to get out. There are a few videos out there on tips and tricks for it, but it is something to note.

I have a brass drift whose sole purpose is for trans filter seal removal. Distort it enough to get a grip with some needle nose pliers and you're done.

 

I change transmission fluid and filter on my 2009 LTZ every 40k miles. Now at 208k miles the original transmission still shifts like new.
It takes 7.5 quarts of Dexron VI fluid to refill.
You can reuse the OEM gasket but make sure it has a metal insert in it. Only that type of gasket is reusable. I also use GM filters.
Don't forget to clean and reinstall the pan magnet. And never use a rag to clean the pan. Lint can be very damaging to your transmission. Use paper towels instead, even to wipe the dipstick when checking the fluid level.