Can't find any solid info on this on the net.
Remove pan and filter (more than one?).
It looks like a plug has to be removed on top since there is no dipstick (oh, what a great idea, that is!) and re-fill until it comes out. Tricky since the car must be perfectly level.
Is this it?
I don't buy into that no dipstick, Jimmy! So if you got a minor leak that needs refilling until its fixed, the average Joe, er' Jimmy, has to take it to GM?!
C'mon, technology (sealing OR fluid) is NOT that advanced where a dipstick is not needed.
Not Good.

 

The 5L40E trans has "Fill for Life"(synthetic) fluid...you should never need to change it as part of a regular maintenance. Of course, they do leak at some point, and they all fail at some point. "Fill for Life"?? My theory is, once it fails, that's the end of it's life, so it needs to be changed.
The fill plug is on the trans itself...another brilliant idea. Fill it till it runs out, drive it, check the level again. There are a LOT of transmissions like this these days. The manufacturers do NOT want anyone "messin with" their stuff. They want DIYers to go to the dealer for service of any kind. The Mercedes(and Chrysler used) transmissions have a filler tube, but....no dipstick. To actually check the level, you have to buy a "special tool", which is really just a check gauge/dipstick...

 

the auto makers have adapted the decades old practice of the standard / manual transmissions & gearboxes. you will also find that practice in all gearboxes like rear ends/differentials, transfer cases (4x4), manual/stick shift transmissions, etc..

point being, these gearboxes should not leak and when they do, its time to do some maintenance on them. if the leak is so bad that it needs fluid added between scheduled maintenance, the leak is serious and theoretically the car could lose all its fluid in a single drive, time to do a repair.

not all of us practice that because we have those dipsticks that helps us control the fluid levels when they leak.

in reality, the engine is the only oil feed unit in a car that can "consume" oil so I expect the dipsticks to remain until all car models include sensors which check oil level constantly & are much more reliable than the human variable.

lastly,the A/C in our modern Cadillacs has already achieved the no visual inspections, by use of sensors that include computer controls to protect and shut down the compressor when fluid is too low.




.

 

Just as I thought.
I will change the filter and fluid sometime by the end of the year.

 

Most new BMW's do not have engine oil dipsticks anymore and its raising quite a stink among BMW buyers. Thankfully, in addition to the electronic sensor, the CTS still retains the "old fashion" dipstick.

 

The new dipstick - your index finger in the filler hole?