04 S80 T6 RPM go crazy on 1st gear

[juny20]

Top it off with approx 7qts of Dexron VI when you are done. I've been pleased with Dexron VI in both the T5 (Aisin Warner AW50 tranny) and the GM 4T65E-GT in the T6. In my case I have done drain and fills only, no flushes. You can use the filter for 2000 Chevy Impala 3800, same filter but if you ask for the filter for your S80, it will probably be twice as much if not more

Hi there! I was going to work on this, but I see you recommend Dexron VI, but my owners manual recommends Dexron IIIG and so this website: volvospeed.com/Repair/s80_transmission.html.

I did a search and the found my transmission should be the AW 50-42LE. Is this right? Which fluid should I use?

[boosted5cyl]

You can use Dexron VI wherever Dexron III is called for, that said I'm not 100% sure on Dexron IIIG.

[juny20]

Thank you! You are right, I found more info about the Dexron VI and Dexron III.
Dexron III meets Dexron IIIG (it seems they are the same).
There is a data sheet about Dexron III here: www.lubadmin.com/upload/produit/FichePDF/lang_29/5420.pdf

Is this a good oil; Valvoline Max Life ATF? Some info here, apparently it is fully compatible with many ATF fluids:
www.valvoline.com/products/consumer-products/automatic-transmission-products/automatic-transmission-fluid/37

Ok, this week it is. I am going to get the oil, filter kit, and will go at it. This is the first time me doing this ever (changing trans fluid and filter) so I hope that it goes well and that it fixes the problem! I will report back once finished.

[boosted5cyl]

I've heard good things about valvoline trans fluid in general. Important to note that what you have linked is not a Dexron VI fluid however. I used Valvoline Dexron VI in my T6 when I first got it, no ill effects so far. That said, when I get the head gasket finished ill be draining and refilling with Walmart "supertech" Dexron VI which has been good for me too and its half the cost of valvoline and suchlike.

Just take your time doing it, especially while refilling as it can be slow to fill.... Im not sure what tranny you have but ive attached some guides from VADIS for reference. They detail more of a flush process, it up to you if you want to to that route or not. Personally I'd do a drain and fill, drive for a week and do another.