Manager Forum

Dexron VI is supposed to be the replacement for Dexron III. According to GM, it should be used in all applications and I'm seeing that OD5 data is reflecting that now. My question is what is actually happening out in the field and what are your opinions on the matter? Are you still using Dexron III?

TIA,

Ric

I have been still using dexIII for all the older stuff. When installing new transmission, then it does get dex 6. All newer vehicles get dex 6. Always went by what book called for, except for the exclusions stated.

For us, any GM now gets Mercon VI. Works well in all applications so far. We like it except for the price.

We are using DEX 6 and Wolfshead synthetic in almost everything.

as we all know i'm fluid specific. the dex issue is a simple one. each level of dex will superseded the other with the exception of synthetic. personally, i wouldn't use mercon in a g.m but that's a personal choice. there are shops that claim the cross use can resolve issues. i'm not one of them. there are chemical engineers that are way more qualified than i am and i've seen results of improper fluid usage. there are "universal" fluids out there and i'm sure if i looked in a walmart, autozone, target, etc i'd find a universal transmission fluid. let it stay on the shelf. oh ya, when you're reading the specs on the back make sure they stand for something. if it say's meets or exceeds all usa guidelines it could mean "you stupid a**" it's like synthetic blends. i've never seen any manufacturer recommend them. will i use them? n.f.w.

ill use dex 6 when ever its called for. were vin friendly around here what ever the manufacture recomends is what we use. i can tell you when atf+4 came out a lot of guys would use rear diff friction modifyer and the old style fluid to make up for the change in fluid properties to save money steven is right in that someone with a lot more education than me designed that system for the use of dex 6. i made a call to a gm trans guy who is still works at the dealer hes advise is do it at your own risk theres a world of difference between dex 3 and dex 6 more non suddsing additive, more friction modifyer, the shift schedule is set up for that fluid. i guess what im trying to say is if the shift schedule is set up for a normal shift then you serv. the trans with a less agressive fluid there very well could be trans issues such as a more sloppy shift where it would kind of slide in instead of a firm or normal shift. i wouldnt know if it would do any hard part damage or not maybe over time if it was flushed with the old stlye fluid i could see brunt clutchs. or i would think shift issues at the min. i hope my ratteling on helps

GM put out a TSB # 04-07-30-037D dated November 21,2007 that says that Dexron VI is to be used in all warranty repairs and is compatible with Dexron III in any proportion. Based on that TSB from GM is why I use Dexron VI in any GM vehicle. I quote from that TSB "Current and prior automatic transmission models that have used Dexron III must now only use Dexron VI." So far, I have not seen any issues, negative ones that is. Actually the comments I have gotten so far is that shifts seem to be firmer and better, one driver even ventured that fuel economy is up since I flushed out the trans and installed Dexron VI. I also questioned a local trans rebuilder in my area and he also uses Dexron VI whenever he rebuilds a GM trans of most any model. I suppose though it is a matter of whatever you as the shop owner want to be comfortable with.

I use valvoline maxlife synthetic in all dex 6 vehicles unless its a really old gm then i use shell multivehicle atf in those.