Confused. Mercon V or Dexron VI?

Messages
8
Location
Northern Hellinois US
Subject at hand: 2011 GMC Acadia Denali AWD. 6T75 auto trans. Had my engine oil changed today, and asked the shop to fill/drain the trans oil at the same time. Job done, went to cash out and the paperwork said MERCON V used, instead of GM spec'd DEXRON VI. Knowing next to nothing about AT feeding and care, I stopped dead and asked "isn't that for Ford transmissions?" Service writer said it came from the Cadillac store in their dealer network, and that it was "the same." Doubtful, I pulled up my pdf of the owner manual and it specs out DEXRON VI. No mention of MERCON V at all. Can someone please confirm that one is the same/same enough as the other? Reading a bit I found that the GM 6T and the Ford 6F series trans are a joint venture, so maybe that was the basis of their assertion? Any help would be appreciated.
 
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35,897
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ME
It's close, but since it isn't on-spec, I'd make them redo it with the right stuff. If for no other reason than they should have asked you/ had your informed consent.
 
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147
Location
New York City
Maybe they used one of those Dexron VI/Mercon V blends. Supertech has one and it's Dexron Approved. If this was a GM Dealer, I doubt they would put the pure Mercon V fluid.
 
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Basehor, KS
Here's what Super Tech says about their Mercon V and "suitable for use": Super Tech MERCON V Automatic Transmission Fluid, 1 Quart: Uses a unique combination of conventional base stocks and an advanced additive technology Meets the performance requirements of Ford automatic transmissions calling for MERCON V fluid Suitable for use where the following automatic transmission fluids are recommended: Chrysler 3 and 4 (except C-604 transmissions) DEXRON II (E, F) DEXRON III (G, H) DEXRON VI Honda Z-1 MERCON MERCON LV MERCON SP Nissan Matic-J Toyota T-IV or Toyota WS Not for use in vehicles requiring Ford Type F fluid or Continuous Variable Transmissions (CVTs) Super Tech transmission fluid provides protection against wear and transmission shudder Resistant to thickening due to high temperatures Provides friction stability to maintain smooth consistent shift performance
 
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MA
Originally Posted by A_User55555
Maybe they used one of those Dexron VI/Mercon V blends. Supertech has one and it's Dexron Approved. If this was a GM Dealer, I doubt they would put the pure Mercon V fluid.
Vavoline Maxlife ATF is also one of those crazy Mercon, V, LV and Dextron II, III, VI fluids among others all in one fluid.
 
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241
Location
Illinois
Mercon v is not the right fluid in any gm product ever. You need to go back and have them replace it with a dexron VI equivalent. Mercon lv is acceptable, and so is maxlife. It shouldn't have hurt anything, but for longevity and peace of mind they should make it right.
 
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1,441
Location
CA
Originally Posted by Jetsfan421
Mercon v is not the right fluid in any gm product ever. You need to go back and have them replace it with a dexron VI equivalent. Mercon lv is acceptable, and so is maxlife. It shouldn't have hurt anything, but for longevity and peace of mind they should make it right.
Agreed. Since GM recommend a licensed Dex VI product, that's what should be used. Mercon V is most definitely not Dex VI.
 
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440
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Southeast
Originally Posted by AcadiaDave
That's what I've done. It never left the shop, actually. Had them get the correct fluid and drain and fill ALL of it.
Are they doing a cooler line exchange or just a drain and fill?
 
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10,456
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Cincinnati, OH, USA
Also, Mercon V is normally a blend, Dex VI is a FULL synthetic. I'd be a little worried if a garage messed up something that simple, I'd be looking for another shop. Funny thing is, Merc V is a lot rarer than Dex VI, and seems to normally cost more!
 
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241
Location
Illinois
Originally Posted by AcadiaDave
That's what I've done. It never left the shop, actually. Had them get the correct fluid and drain and fill ALL of it.
I'm not sure a drain and fill would get all of it out after it's been run. Pretty sure it takes at least 3 drain and fills on that particular transmission to get most of the fluid renewed.
 

AcadiaDave

Thread starter
Messages
8
Location
Northern Hellinois US
Sounded like a cooler line exchange, the service writer said "flush." I insisted on all of it being replaced, so if ill things happen after this it's on them - I made that clear as well.
 

AcadiaDave

Thread starter
Messages
8
Location
Northern Hellinois US
Originally Posted by Miller88
Isn't that transmission used in different Ford products anyway?
It's that joint Ford/GM project unit. Ford calls theirs 6F, GM 6T. So probably, but it's had Dex-VI in it as long as I've had it.
 
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13,196
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Maricopa Arizona
Originally Posted by AcadiaDave
Originally Posted by Miller88
Isn't that transmission used in different Ford products anyway?
It's that joint Ford/GM project unit. Ford calls theirs 6F, GM 6T. So probably, but it's had Dex-VI in it as long as I've had it.
MERCON LV/DEXRON VI are the same or so close it doesn't matter because there are products which have both licenses in a single bottle.
 

AcadiaDave

Thread starter
Messages
8
Location
Northern Hellinois US
Originally Posted by Miller88
MERCON LV/DEXRON VI are the same or so close it doesn't matter because there are products which have both licenses in a single bottle.
Problem is, they said Merc V, not LV.
 
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1,231
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PA
Going to be doing a drain and fill on the Crown Vic soon. Should I stick with Mercon V or is Maxlife Full Syn ATF a better choice?
 
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2,650
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San Rafael, CA
Originally Posted by umungus1122
Going to be doing a drain and fill on the Crown Vic soon. Should I stick with Mercon V or is Maxlife Full Syn ATF a better choice?
Either one will be fine but I always used the thicker Mercon V in my three Vics vs the thinner Mercon LV.
 
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440
Location
Southeast
Originally Posted by dogememe
Originally Posted by umungus1122
Going to be doing a drain and fill on the Crown Vic soon. Should I stick with Mercon V or is Maxlife Full Syn ATF a better choice?
Either one will be fine but I always used the thicker Mercon V in my three Vics vs the thinner Mercon LV.
X2, I'd stay with Mercon V. Maxlife would probably be fine, but Mercon 5 is a pretty good fluid, cheap and readily available. I don't see any reason to venture outside of what's recommended here.
 
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