Dex-VI, Dex/Merc-III, Nissan Matic D???????

[NightRiderQ45]

My Q is getting up there with age/mileage and the only "weak spot" for my generation is the tranny. Since 200k, I've been doing 4qts drain & fill with ST Dex-VI every 15-20k. Well the time has approached and I have a question. After going thru my father's shed, I found 1qt of Nissan Matic D (which my manual calls for), and I quart of Coastal Dex-III (the real licensed stuff). Both had dust on the bottles, but were un opened. Since Matic D is basically Dex-III, and I have two new bottles of Dex-VI laying around, can I use all 4qts to do my drain and fill? I don't know what would happen mixing those three different brands.

FYI...I'm not cheap and can go purchase the other two Dex-VI bottles if needed, but I just wanted to see if my first option was feasible.

 

[440Magnum]

Dex-VI is significantly lighter viscosity than D-III. I've switched over to ATF +4 in my Dex-III applications, but then mine are all Mopars anyway (except the Jeep's Aisin AW-4, but ATF+4 is approved for it also and is used as a service fill in Jeep service departments). I'm not sure if there's a downside to running ATF+4 in a Nissan, but I'd be wary of Dex VI unless that's what Nissan has gone to in their own service departments. I've read rumors (and that's all they are) that Dex VI isn't nearly as backward compatible as all the previous Dexrons were, which are basically backward compatible all the way to the ancient "Type A" transmission fluid from the 50s. The lower viscosity of Dex VI is NOT a rumor- that's real.

 

[JHZR2]

Besides switching brands and being unsure of the age of those bottles, Id not be very concerned. Chances are you did/do have a mix of all those anyway.

I think your process is sound. Most important is fresh fluid. Dex VI is a viscosity roughly the same as the sheared viscosity of dex III.

 

[pbm]

I'd probably pick up 2 qts. of Dex III at WM and mix it with the 2 that you already have. I doubt it would make a difference at a 15 to 20K OCI. Dex VI is thinner and probably not suited well for a hi-mileage Nissan. I would try Pennzoil Multi-Vehicle or Castrol Hi-Mileage and see how it feels.

 

[dnewton3]

Just so we are clear on some of the long term applications of the DEX products, here is a thing to note.

The former licensed DEX III fluids, and the current "marketed as" DEX/Merc fluids, do indeed start with a higher vis than does DEX VI. However, the vis retention of DEX VI is much greater, so much so that it holds it's vis "better" on a 2:1 ratio against the older III. As the DEX III ages, the vis actually drops below that of DEX VI. The oxidation resistance is also approximately 2x as good as well in favor of the DEX VI.

The downside to the DEX VI is that the mandated chemistry package (to be licensed) can occasionally have an adverse affect on some seals. Allison specifically warns against the use of DEX VI in older trannies, and therefore has a "cut-off" for DEX VI use. Later, they upgraded some seals to be compatible with the DEX VI. I suspect this may or may not be the case in other situations (other brands of OEM) as well, but who knows for sure? GM obviously believes that DEX VI is fully backwards compatible, but their (former) tranny partner says otherwise.

Food for thought.

 

[NightRiderQ45]

Thanks for the response. Dex VI is definitely better than Dex III because it stays in viscosity longer. It starts off thin, but stays in that range where as Dex III starts off higher and immediately shears below the range/viscosity of Dex-VI. I can't remember the link, but somewhere online showed data to prove what I stated before. At 200k, my tranny had all M1 syn Mercon V. After the 4 qt chance at 220k, it now has a mixture ST Dex-VI and still some old M1 Mercon V.

I was afraid to mix 2qts of ST Dex-VI, 1qt of Nissan Matic-D, and the 1qt Coastal Dex/Mercon together. I didn't know if the additive package would react negative with each other. I can go purchase the addition 2qts of Dex-VI, but I hate to just leave two good unused quarts laying around.

 

[SteveSRT8]

There shouldn't be any issues in mixing a small amount in. 2 quarts is a small percentage overall.

 

[NightRiderQ45]

Thanks again. I'll go ahead and use the two left over quarts.

 

[MaximaGuy]

Originally Posted By: NightRiderQ45
Thanks for the response. Dex VI is definitely better than Dex III because it stays in viscosity longer. It starts off thin, but stays in that range where as Dex III starts off higher and immediately shears below the range/viscosity of Dex-VI


Which fool told u that the vis will hold better with DexVI -- all ATFs loose vis over time?
When I drained my DexVI from my maxima sometime back it came out like water.. Nissan trannies chew up fluids like no tomorrow and DexVI is not recommended, period.

Stick with Castrol MV Import ATF.

 

[ABomb369]

Originally Posted By: MaximaGuy
Originally Posted By: NightRiderQ45
Thanks for the response. Dex VI is definitely better than Dex III because it stays in viscosity longer. It starts off thin, but stays in that range where as Dex III starts off higher and immediately shears below the range/viscosity of Dex-VI


Which fool told u that the vis will hold better with DexVI -- all ATFs loose vis over time?
When I drained my DexVI from my maxima sometime back it came out like water.. Nissan trannies chew up fluids like no tomorrow and DexVI is not recommended, period.

Stick with Castrol MV Import ATF.


You are correct in stating all ATF will lose viscosity, however, it is stated in a GM TSB from the release of DexVI regarding it's improved properties and one of them is viscosity shear stability is 200% improved over DexIII.

I am not saying it is right for this application but calling somebody a fool over a documented statement is a little harsh.

TSB No.: 04-07-30-037D for the record.

 

[unDummy]

Coming out like water means nothing. A UOA would be needed to determine the visc.

If you looked at a lot of UOAs, regular dex/merc would start out at 7.5cst and shear down to 5cst and even less. Have any UOAs of DexronVI to see if it was worse???
Would you rather use a fluid that starts out at 7.5cst and shears to 4.5cst, or one that starts out at 6.2 and shears to 5.5cst? This fool says unless you can prove it with a UOA, you shouldn't start name calling. Nissan transmissions are no better or worse than any other automaker when it comes to fluid abuse.

NightriderQ45, feel free to use the 4 quarts of whatever mix you have for the current interval, and continue with whatever ATF you want for the future intervals.

 

[SteveSRT8]

Anyone using Dex VI in a non-GM application is taking a risk.

But anyone who reads the spec would have to agree it is a superior fluid. May be the best available, but at least very good.

 

[NightRiderQ45]

Originally Posted By: MaximaGuy
Originally Posted By: NightRiderQ45
Thanks for the response. Dex VI is definitely better than Dex III because it stays in viscosity longer. It starts off thin, but stays in that range where as Dex III starts off higher and immediately shears below the range/viscosity of Dex-VI


Which fool told u that the vis will hold better with DexVI -- all ATFs loose vis over time?
When I drained my DexVI from my maxima sometime back it came out like water.. Nissan trannies chew up fluids like no tomorrow and DexVI is not recommended, period.

Stick with Castrol MV Import ATF.

Buddy you have been sounding foolish regarding anything with Dex VI and basically any atf. You are the guy who stated that ALL ATF'S suck after 15k and doesn't hold up at all. You even went as far as said that syn atf is shot after 20k! Come on dude, I don't think anyone here takes your aft recommendations seriously. Everyone please read his past posts that simply states how confused he is. I called you out once before about your statements and I have to do it again.

Originally Posted By: NightRiderQ45
Also MaximaGuy...I found one of your old post from late Oct. about ST DexVI and you said that you didn't have any issues with the fluid in 13k; so how all of the sudden your tranny was slipping in 10K??

Originally Posted By: MaximaGuy
BTW, I have ST DexVI in my 00 maxima and have been quite happy with the results, nothing remarkable but on the same not nothing negative to say too.

All ATF fluids "suck" once they hit the 15K mark. Having said that, I would use ST with OCIs.


Another one of your post that conflicts with the 10k you listed while your tranny was slipping.

Originally Posted By: MaximaGuy
I have 13K on the ST DexVI and my Maxima tranny has recieved all kind of OTC soups except Amsoil on my tranny.

Nothing, I mean nothing holds up beyond 20K, u can take my word on it. Almost all miles are highway and to be honest I don't drive it like a 60yr old, I drive it well for what it is designed for (though I never abuse it with WOT etc).

I have 170K on it and the reason it has lasted this long is becoz the fluid has been exchanged frequently.

All ATFs worked the same on my tranny, the best results were Castrol Import ATF, all others including M1 suck when they hit 15-20K miles, period.

Could you please provide any FACTS THAT all atf's are basically shot after only 20k?? Funny that there are cars out there who never changed their aft fluid and still running. Below is your response and another member called you out too.

Originally Posted By: Toros
Originally Posted By: MaximaGuy
True, with a drain/fill with 4Q removed the tranny work predictably.

I did another drain and fill with DexVI it started to slip at around 10K miles subsequent to the change. In and around half way thro the tranny started to act up, I had changed my revoln sensor and thought that may have been the problem, but when I got all of the DexVI out, the tranny settled down and the shift points were predicable.

So essentially the fluid with 2 drains/fills was getting thiner.

In short DevVI is NOT a solution for Nissan trannies. Period.



Seems to me and others that you are just plain confused and your recommendations/advide should never be taken seriously.


Do you NOT KNOW that Dex VI is an improvement over Dex III???? Dex III start off high and vis drops immediately below the viscosity Dex VI starts at; whereas Dex VI starts thin and stays in viscosity. This is proven, is a FACT, and if you don't believe that, why do you refute GM claims with you OWN FACTS instead of your "came out like wine" bullsh*t statements. I've been using Dex VI since 200k and I have NO issues. My brother's 96 Maxima is using Dex VI at 250k on his tranny with NO ISSUES!

So what I would like for you to do is show FACTS where Dex VI isn't an improvement over Dex III as far as staying in viscosity and provide ALL of the Nissan trannies that were destroyed with using Dex VI. Since I know that you can't provide this, please stop making yourself look foolish with your asinine comments ok. You tranny isn't a blueprint for all nissan trannies out there.

 

[MaximaGuy]

NightRiderQ45: I have no time on my side to look thro posts to correlate if one post is contradictory to another. Period.

DexVI doesn't work for my tranny and I have no confidence in it. All the tall claims about backward compatibility is a gimmick, I have driven my maxima for 187K and can feel every shift to notice what is cooking inside.

DexVI is not for Nissan trannies. Period!!!

 

[NightRiderQ45]

Originally Posted By: MaximaGuy
NightRiderQ45: I have no time on my side to look thro posts to correlate if one post is contradictory to another. Period.

DexVI doesn't work for my tranny and I have no confidence in it. All the tall claims about backward compatibility is a gimmick, I have driven my maxima for 187K and can feel every shift to notice what is cooking inside.

DexVI is not for Nissan trannies. Period!!!

Please provide FACTS. That's all I'm asking for. Just provide facts, heck I'm not the only person in this thread asking to you back up your claims!!!

I will continue to use my Dex VI in my Nissan(s) tranny with no issues. Thanks for the responses everyone. I'll mix the other two qts and go from there.

 

[MaximaGuy]

BTW I am not preaching to anyone to use it or not. I am posting my observations on my tranny, that's it. Now having said that each one is on his own, go ahead and use it and post your opinions.

Older trannies (say with 200K miles) are ticking timebombs and anything out of the ordinary will break it or result in premature death.

Does anyone want to take the risk and kill a worn out tranny and look back at DexVI and look foolish. I don't and many on the forum don't, the posts from my end to educate the risks of using super thin ATFs.

 

[MaximaGuy]

Originally Posted By: NightRiderQ45
Please provide FACTS. That's all I'm asking for.


Dude, f...k the facts, I am not going to tell u my tranny was killed using DexVI. I am not going to have my tranny as a guinea big for that foolish experiment. You are more than welcome to try it out and if you tranny is shot, make it a point to post your foolhardiness (not may have the guts to post their stupid decisions, that is the nature of human beings).

If you drive a vehicle for 200K one will know every heartbeat of the vehicle, I don't need to kill my tranny to make a -ve post on the forum about DexVI.