My transmission fluid is low. I ran over something in the road a while back and worked with my brother in law to change out the transmission fluid and replace a broken part (forgot what the part was, but it was a relatively small plastic piece that the fluid flows through). We had to purchase the part from Volvo so we went ahead and purchased the ATF there as well. The fluid is not leaking but it is definitely low (brother in law thinks we may not have put enough in last time?? Unsure of the reason).
So I'm curious what alternative brands I can use for my transmission fluid? Also, since we're adding a little would you recommend draining and refilling using all new fluid or just filling it up with a little extra? I checked with the dealer and they only sell the fluid by the gallon for $90.
Last question - does anyone know the capacity of the ATF for the 09 S40?
Thank you in advance for your help! I apologize if this has already been discussed - I searched for 30 minutes and wasn't able to find anything answering my questions (I am a newbie, tho!).

 

fluid type and capacity is in the Owners Manual. For the non turbo automatics the manual calls for JWS3309 spec and a capacity of 8.2Qt (7.75L). You'd only see the full capacity if you do a full flush (say by tapping the cooler lines). A drain and fill would be about 1/3rd that amount.

Owners Manuals are also online:
Volvo Cars US Support Home Page

 

Thank you for the quick response and the link!