1xsculler

How do you add Automatic Transmission Fluid to an '07 GL450. I can't find a dipstick/filler tube but there is a large Torx fitting on the rear side of the tranny. Is that where you fill it?

alx

You don't add fluid in the normal sense of the word. You pump fluid through the drain until it overflows from the filling tube which is above the filling hole. Search 7g transmission fluid change to gain better understanding of the process

Anything tranny related is better left to the dealer. For example a fluid change is $350-400 and knowing what is involved it is actually a deal anybody should take in a heartbeat.

sak335

To expand on this, you need to buy an adapter that screws into the drain hole on the transmission pan. Now, when you unscrew that bolt, a few quarts of fluid are going to drain out first. Isn't this fun? I bought a Mityvac branded adapter off Amazon for about $14 shipped.


My suggestion is that if you need to add fluid, and are anywhere near needing a full drain and fill, that you do a complete transmission service (change out the 9L of fluid and the filter) since you'll be in there anyway.


The fluid is fairly expensive ($14-25 per liter) and you need at least 10 L to do a service. Also, the pan bolts are not reuseable and must be replaced. While not necessary, the torque converter drain bolt is easier to replace than to reuse, and cheap. A full service, DIY, costs about $250 and I believe the dealer usually charges $500+


I just did mine a month ago, and it was tedious and messy, but easy.