I just purchased an 03 S40 with the 5sp AT and 20,000miles. I like to overmaintain my car and want to do a drain and refill but the Volvo dealer does not recommend it saying it is a "lifetime fill" and leave it alone. They also recommend DexronIII/Mercon as a fill which is against all that I read where the called for specification is JWS-3309. The dealer does not even carry the Volvo brand. My question is, can I use any JWS-3309 specification fluid to do a drain and refill as I have Toyota cars and Toyota T-IV fluid is also a JWS-3309 fluid and I have a reasonable source for this fluid. My logic is that DexronIII/Mercon and ATF+3, and Type F come in many different brands, and so I'd think that any reputable brand of the JWS-3309 would be satisfactory. Thanks for your time. Bill

 

You can use whats is called for by your source.
Where di you get the info?
Just make sure they are pretty much the same fluid as what Volvo says to put in.

 

The owners manual for my S40 indicates that the specified AT fluid has to meet the JWS-3309 specs. I've visited an "oil and lubrication" website where the information about the different fluids meet JWS-3309 specs and they mention Toyota T-IV, Saab fluid for the 5sp AW transmission, the Mazda AT, and a couple of others. Mobil makes a JWS-3309 AT fluid that is referenced in their website, and mentions the above cars and says their fluid is compatible, but I can't find any source for this fluid locally or on the internet in my searchs so far. Thanks for your reply-Bill

 

Im not sure where to go from here.Maybe if you can't find it you will have to have the dealer order it.