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Barney Eaton

Dexron VI auto trans fluid

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Just added an auxiliary transmission cooler to my 2017 Enclave and needed some ATF.    Checking the owners manual I discovered it required Dexron VI and the Dexron III I have on hand cannot be used.

Purchased a gallon container of Valvoline Max Life ATF at my closest source O'Reilly's auto parts.......thought that would be plenty to do the job.   While doing the install,  the trans fluid looked a little dark

and the vehicle only has 17K so I made the decision to flush the factory fluid.    Another trip to town and this time went to WalMart and they had the Valvoline Max Life so I purchased 2 more gallon containers.

The purpose of this post is to let you know if you have a GM vehicle made after 2005 it probably uses Dexron VI.   

 

The second part of the story is cost and availabity.   WalMart price for a gallon of Valvoline = $17.97   Auto Zone & O'Reilly's  = $27.99,  Advanced Auto Parts = $21.98 (price may vary in your area) 

All had the Valvoline gallon containers....WalMart did not carry any other brand or size (quart) of the Dexron VI.   AutoZone had quart containers of their house brand for $8.99.  

If you are driving a newer GM vehicle,  check the owners manual for the type of ATF you need and maybe you want to get a quart to have on the shelf.

Here is a link to history of Dexron ATF...... https://en.wikipedia.org/wiki/DEXRON#2013_-_DEXRON-HP

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Dexron has been improved over the  years.  You can use a newer version of it for older vehicles, but you can not use an older version for newer vehicles.   Like in your case, you can use Dexron 6 in all current vehicles that call for it and older vehicles, but not use Dexron 3 for newer vehicles.

 

FYI, automatic transmission fluid is about 80% base oil and 20% additives which include anti foaming agents, anti corrosion agents, cleaners,  etc...

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Thanks Larry..........I failed to mention Dexron VI is downward compatable

If you read the link.... Dexron HD is even newer ....made for the 8 speed automatic

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Dex VI started with the 6-speed automatics.  It can be used in ALL prior GM automatics which take a Dexron-family fluid.  Which is all the way back to 1949, according to their literature.  Dex VI is a semi-synthetic ATF, whereas other Dexron-family fluids are just normal oil.  The still-newer 8-speed automatics can take a Dexron HP full-synthetic atf, which is even MORE expensive.

 

The prior Dexron III-spec oil is available in ACDelco, but without the "Dexron III" nomenclatures.  In other brands, it can be listed as "All Makes" AND specifically mention GM vehicles on the bottle.  Other "All Makes" can specifically mention Honda and others-than-GM or Ford.

 

WalMart seems to have the marked on low-priced oils!  A 5 qt jug of Castrol Edge (black bottle) was $27.00 at WM, and $41.00 at O'Reillys.  A 4-qt jug of Rotella T5 10W-30 was about $17.00 (T5 is semi-syn).

 

Be sure to check WM for prices on ACDelco oil filters, too!

 

NTX5467

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What happened to Dexron and Dexron II??? Guess I is old enough to remember when.... Dandy Dave! 

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Hey, my Dynaflow calls for Type A

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5 hours ago, RivNut said:

Hey, my Dynaflow calls for Type A

 

 

5 minutes ago, Larry Schramm said:

 

Dex 6 will work.

Can we pin this?  I feel like this has come up offer in the past.. Maybe even by me 😜

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1 hour ago, Larry Schramm said:

 

Dex 6 will work.

Figured it would based on the previous posts.

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Dandy Dave,   Orig Dexron (Dex I) was upgraded and "Dex II" happened.  Additional additives to keep the automatic trans coolers from having  issues?

Dex II became Dex IIE when we got electronic valve bodies in the automatic transmissions, which later became Dex III.  From my experience, adding the GM Automatic Transmission Conditioner to Dex II made it act more like Dex IIE, a bit quicker shifts, IF you paid attention to such things, in my '77 Camaro THM350.  Almost as nice as putting Type F Ford atf in them.

 

Dex VI happened (Dex V was skipped, possibly to prevent confusion with Ford's Mercon V fluid, which some aftermarket companies combine that application with for their Dex III fluids).  Ford had been using Dex III since they stopped their earlier Type F licensing, then replaced it for their applications with Mercon V.

 

As mentioned, Dex VI is a semi-synthetic fluid.  Formulated for the then-new 6-speed automatics (6L80 in light-duty truck chassis vehicles) which had "clutch-to-clutch" shifting (whatever that means).  When GM introduced that, they ceased to license Dex III fluid, as the Dex VI was backward-compatible with all other GM atfs, per their literature.  As the aftermarket ceased to use "Dexron III" prominently in their product designations.  ONLY in the fine print on the backside of the bottle might you see any reference to that.  The recent ACDelco-branded atf does not mention it either, but it clearly is Dex III oriented, being "dino" rather than "semi-syn".

 

I'm not sure what would happen to a Dex VI-rated automatic trans if you put Dex III-rated fluid in it.  Don't know that anybody has deliberately investigated that, either.  I just know that GM literature says to use ONLY Dex VI in the newer 6+speed automatics, unless they sped the full-syn DexHP fluid for them.  Considering the rebuild/replace cost of the newer automatics, the addition cost of the Dex VI fluid is a good investment, to me.

 

NTX5467

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Would there be a problem with adding some Dex VI to a transmission that has Dex III in it?  i.e. Can they be mixed?

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What about the products which are labeled "DEXRON-MERCON"?

Can they be used in my:

'02 Suburban

'95 Fleetwood

'88 Corvette

'54 Caddy

'06 Avalanche

'00 Excursion

 

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Posted (edited)
13 hours ago, Marty Roth said:

What about the products which are labeled "DEXRON-MERCON"?

Can they be used in my:

'02 Suburban

'95 Fleetwood

'88 Corvette

'54 Caddy

'06 Avalanche

'00 Excursion

 

 

DEXRON-MERCON I believe is the name for the fluid that was used by both GM & Ford.

 

Marty,  If they were my cars, I would put Dexron 6 in all of the cars. Makes stocking trans fluid easy.  One type for all vehicles, plus it is the most recent formulation.

Edited by Larry Schramm (see edit history)
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I understand Dexron 5 is full synthetic and should NOT be used in our Dynaflows as it will attack the natural rubber (Buna N ) etc.

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The Valvoline Max Life ATF that I mentioned in the first post is a synthetic.

 

I also found this temp gage that I will be adding to check the transmission temperature........neat little read out that was only $7 on Ebay.

I may need to extend one of the wires.   In a trial run, I positioned the sensor on the cooler line,  split a 1 in piece of tubing and used that to hold the sensor in place.

the display works on something like 4 to 20 volts DC...... tried it on my '39 with a 6v system to get a more accurate water temp reading and it worked there.  Problem is where do you hide a modern 7 segment display on an 80 year old car?

 

p.jpg

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There was NO Dex V, so it would not be confused with Mercon V, apparently.  Dex VI originally was semi-syn in the GM part number.  Other brands can have synthetic fluid at their desire, as always.  The DexHP is full syn AND more expensive, mainly used din modern 8-speeds in particular vehicles.

 

Many of the newer atf types, are "friction-modified" to deal with how the lock-up torque converter is modulated by the ECM.  Not just WHEN it locks up smmooooothly, but what percentage of lockup in those modes, too.  Which results in equipment that can handle the partial lock-up mode for extended periods of time via the oil base stocks (usually part of full synthetic in addition to the related additive package.

 

Key thing to notice is that even if the particular brand of atf is synthetic, that it ALSO needs to be "Dexron VI" rated!!   OR mentions use in the particular model year of your vehicle.

 

IF you have a newer GM pickup (possibly Ford and Dodge/Ram have it too?), there can be a DIC readout for "Transmission Temp".  For the trailering uses, I suspect.

 

I'm not sure there would be much to gain in  using Dex VI in an older vehicle, just because you can.  When prior-spec Dex III fluid is still around, just not labelled as such, as I mentioned above.  GM does indicate that Dex VI is backward compatible all the way to 1949, though.  Your judgment call.

 

Compatibility with prior GM atf?  Remember that unless your torque converter/coupling has a drain plug, when you drain the pan for a fluid/filter change, the torque converter still has (the fluid being otherwise changed) atf in it.  Plus some of the innards, too., as a "rebuild" atf refill capacity is more than just a "fluid and filter" change capacity.  Be that as it may.

 

NTX5467

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Posted (edited)

Willis........the trans temp reading on my GMC was what prompted me to want to know the temperature on my other vehicles.

 

Ben,  here is the link to the temp display and the actual price is $7.98 including shipping and there seems to be no limit to what you can measure.

It comes with a jumper in the back which causes it to read in Centigrade....pull the jumper and it reads Fahrenheit

It is apparently designed to use on computer equipment as it has a 4 pin male/female jumper (like the one that plugs into a hard drive)

The display only uses 2 wires .....the input DC voltage and ground.   The probe I think said it could be put in liquids....I am just attaching it to the outside of the steel tube.

On the '39 I plan on attaching it to the radiator connection.

The only negative might be the display is probably not waterproof.

Link = https://www.ebay.com/itm/Fahrenheit-Centigrade-Digital-LCD-Thermometer-Temperature-Meter-Gauge-C-F-PC-MOD/271757794116?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

Here is a picture of the way I plan on permanently attaching the probe to the transmission cooler line.

7 segment.jpg

Edited by Barney Eaton (see edit history)

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Generally, "dino" atf starts to have issues above about 270 degrees F.  A syn-blend of full-syn should go higher, I suspect.

 

Did the atf you got, Barney, meet Dex VI specs?  Just curious.

 

Just some thoughts,

NTX5467

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On ‎7‎/‎11‎/‎2019 at 8:44 AM, PFindlay said:

Would there be a problem with adding some Dex VI to a transmission that has Dex III in it?  i.e. Can they be mixed?

One would hope they can be mixed, as doing a complete fluid flush is all but impossible without disassembly.

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ATF flush machines have been around for quite some time.  Most new car dealers offer that service.  Changing the filter is extra.

 

GM might not be licensing prior Dex family fluids any more, but Dex III equivalents are still available, even from ACDelco, just no mention of it being Dex III per se, on the bottle.  Just as Ford ceased to license Type F fluid years ago, but aftermarket versions have always been around (might have to search for it in more recent times, though).

 

NTX5467

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11 hours ago, NTX5467 said:

ATF flush machines have been around for quite some time.

 

True, but they don't flush the transmission well enough to permit the introduction of an incompatible fluid.

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Posted (edited)

"I would not suspect Dex VI of being "incompatable with prior Dex family fluids.  Or any other atf for that matter.  It's the trans design that makes pre-Dex VI imcompatible, where applicable (i.e., 6+ speed GM automatics).

 

Back in the '70s, there was an orientation that different brands of engine motor oil would not mix.  THEN it was mentioned that every brand of motor oil that met a particular Military Spec would mix with no problems.  Reason, the Military bought what was the least expensive at the time of the purchase.  Therefore, all brands would mix with no problems.  I suspect similar with any Dex family fluid in any GM automatic which came before the 6 speed automatics of the 2000s.

 

When drain plugs were deleted from the torque converters, there was a concern about the old fluid still being in there.  It was mentioned that the new fluid would replenish the various additives in the old fluid, so no issues.  Of course, back then all we had was Type A or Dexron.

 

For those who put Type F in their GM automatics for better shifting, I knew of no related failures that could be tagged to the fluid change.  So it had to mix with the Dex family fluids, too.

 

As GM had made their Dexron family fluids backward compatible to 1949, there should be no issues with putting the newer fluid with the prior fluids.  Be that as it may.

 

NTX5467

Edited by NTX5467 (see edit history)

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