The owner's manual for my 89 740 GL specifies DEXRON IID automatic trans fluid. Since this is no longer in production, would I be correct in assuming that DEXRON III is compatible? Or do you recommend the proprietary Volvo products?

I just acquired this car and the fluid looks pretty neglected: I was thinking of taking it to a shop for complete fluid replacement. Does this sound like a good idea? Thanks for your help.

Steve

Agree with Kenric, except that AMSOIL synthetic ATF is my choice.
If your fluid is reasonably clean, go right to synthetic. If it looks at all nasty, then a flush with non-synthetic is a smart move (before going synthetic)

That is correct. Dexron III exceeds Dexron IID. If you have the money for it, you might want to consider Mobil 1 synthetic ATF, but it definitely costs a pretty penny. 12 quarts for a complete and total flush at about $4.50 a quart comes out to almost $60.

It's been suggested to use cheapo stuff to flush out the system, run it for a while, and then do another flush soon afterwards with Mobil 1, so that you don't contaminate the Mobil 1.
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Kenric Tam
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'