The owners manual says Dexron II for my 92 Legacy's automatic trans. Is Dexron III/Mercon a acceptable fluid? I have 5 bottles left over from my 87 GL's tranny change & am wondering if I can use it. Thanks.

 

Pat Callaghan

92 Legacy AWD Wagon

Stick with the correct rating, you can't be sure what will happen if you choose a different fluid.

Dexron III is the current standard of ATF and I would definately use that and not buy/use Dexron II. Dexron III is fully compatible with II but much better.

Setrights advice is correct. There are severe incompatibilities betwenn some ATF fluids. I got that education the hard way many years ago. Be careful.

applegump, when do you come up with this theory?

 

The gearbox was designed to use a specific fluid. Characteristics include internal friction, hydraulic stability, seal treatment, temperature sensitivity. Dexron III is different, but not necessarily better.

The parts stores in my neighborhood don't even carry Dexron II.. Only Dexron III.. I use it in my camry and as power steering fluid for my soob and my camry, even though the manual for both cars call for Dexron II.. Dexron III is what there is now.

Thanks guys. I changed my tranny fluid with Dexron III today. It did not help my torque bind but it is cleaner.

 

Pat

I'm glad it worked out OK.

btw - the 'original' Dexron (dexron 1 we'd call it now I suppose) contained about 2% WHALE OIL!

 

BTW- is there a 'synthetic' or other 'high tech' version of ATF fluids?

Yes, Mobil 1 has synthetic ATF. I use it in manual trans that call for ATF, I think it shifts smoother.

 

 

I don't even know where to find dextron II. You can still buy it?

 

I just throw Dextron III into everything, and haven't had a problem.

 

How about this? The Jag calls for type G. It's not even made anymore. There is dextron III in it right now, but im gonna have it flushed out and type F put in it (for its high friction coefficient).

 

And I put type F in a freshly rebuilt turbo 350 for the same reason. No problems there, either.

If you want to get technical, dextron III supercedes dextron II.....just like part #'s

I have been using Valvoline's Synthetic Blend Dexron for quite some time now. Very happy with it, and it is much cheaper than real synthetic. I still change it and the filter every 30k though.

 

Of course most of the big synthetic players have their own version of Dexron. I can't bring myself to spend $6-$8 a quart for the real thing.

Mobil ATF 220. Mineral Dexron II rating.

setright,

do you still use API SG oil in the engine? My '90 Legacy owner's manual states to use API SG but nowadays, modern oils are SJ, SL. Dexron III is an imrpoved (better) version of II, its as simple as that. It has better heat stability etc. If it were incompatible it would say on the bottle and probably be called something different, like ATF TQ. Take brake fluid, Dot 4 is better than Dot 3 and compatible, just better heat range.

One last thing, nowadays you can't get API SG or Dexron II anymore because they have been superceeded.

Erm, that's why I mentioned Mobil ATF 220, it's a Dexron II and still available over here - in redesigned bottles, so it ain't a dead product yet.

 

DOT3 and DOT4 fluids are not to be mixed. There is a "higher" DOT rating for silicone hydraulic fluids, but it would be lethal to use it for normal road applications because it won't mix with water has a lower density. That means that any water in the brake pipes will work it's way into the lowest part of the system, ie. the calipers! But hey, it's called DOT5.1, so it must be better than DOT4

 

Almost ALL fluids have written on them that they are compatible with anything else. Balony, says I! I stick to one brand and type at time.

There is a reason it says they are compatible....it's because they are. It may not be best practice to do so. The boiling point temps really won't mean squat is one thing.

 

Dot 3, Dot 4, & Dot 5.1 are compatible and can be mixed. I wouldn't recommend mixing all those, but they can be mixed.

 

Dot 5 is the silicone based brake fluid and it CAN NOT be mixed with Dot 3, Dot 4, & Dot 5.1. It's also not recommended for street use since it does not absorb water.