The transmission fluid on a Volvo 850 is added to the filler tube. This is accessed by removing the dipstick and inserting a funnel.
dextron III or IV
Hi! My Volvo is a '95, but probably it's the same. open hood, and close to you, on driver's side, is a yellow handle of plastic dipstick.
you don't volvo 850 transaxles do not have a filter for the transmissions they are AW50-42le trans axles the best you can do is a fluid flush
Aeration.
There's no Volvo 850 2000. What you likely saw was a S70.
Well it sounds to me that you either have a leak in your oil pan, or your transmission.
have a look at this dunno if this might be ithttp://au.geocities.com/ozbrick850/transaxle.jpg
Atf dexron iie/iii or ford mercon
It's a sealed transmission. You'll have to take it to a Volvo dealership.
Volvo says that their automatic transmission has a lifetime fluid that does not need to be changed. On the other hand, most experts recommend replacing the transmission fluid every 30,000 miles to extend transmission life and prevent premature transmission failure.
Volvo tries to charge and arm and a leg and a pinky for their Volvo Transmission Fluid. The fluid is the same as Mobile 3309 transmission fluid. You can also use Toyota's T4 fluid as well. Both cost a FRACTION of the cost of what Volvo charges. And on top of this, I spoke with a transmission place, and they told me that a standard $80 fluid change is all that's needed and that you don't even need any "special" transmission fluid. This latter point is on you to decide. Speak with a transmission specialist and also research with Google about the Mobile 3309, you'll see.