Can someone sort out confusing Mercon types?
 

At some point I want to change the fluid and filter in my auto trans (1997 4.6l 4WD). Now the dipstick and my owner's manual say "Mercon," but the Chilton's manual says "Mercon ATF fluid (Dexron Mercon III). It's a 97-00 Chilton's.

So, is it just plain ol' Mercon or is it Mercon III or ????? And, if it is Mercon III, where do I find it at a decent (ie., not at a Ford dealership) price? Is the "combo" stuff OK to use...the stuff at Wal-Mart that says "Dexron-Mercon?"

Thanks in advance.

Actually it's just Mercon or as you'll find it labled, Mercon / Dextron III ATF. You just don't want to use Mercon V. The 2 Mercons are not compatable but Ford uses both in different tranny's.

Actually, if you have the 4R70W tranny, using Mercon V is just fine. Ford shifted to filling the 4R70W with Mercon V sometime after '97, I don't know exactly when. If your tranny came with Mercon V in it (the '97's didn't), then you cannot use regular Mercon in it. The dipstick should identify if this is the case. If the tranny came with regular Mercon in it, then you can use either, just don't mix the two willy nilly. I believe Ford had a TSB at one time mentioning that Mercon V was OK for all 4R70W trannies in these trucks.

In my case, I am running Valvoline Durablend ATF, which meets both Mercon and Mercon V requirements.

There are other trannies that cannot use Mercon V, but I don't know which ones off the top of my head.

Oh, and yes, the regular old Dexron / Mercon ATF should be just fine to use.