Long-term Experience with Valvoline MaxLife Multi-Vehicle ATF in 4R70W, Anyone?


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Sep 22, 2023
Richmond, VA
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There's no better way to light up an automotive online forum than starting a conversation about engine oil.

Is transmission fluid just as controversial? Let's find out.

See the subject line: I'm interested in actual experiences with Valvoline MaxLife Multi-Vehicle ATF (hereafter MaxLife for short) in 4R70W transmissions.

Let's cover the basics: of course conventional wisdom is to use the fluid specified by Ford, i.e., Mercon V which replaced Mercon. Mercon V is widely available from various brands, including Motorcraft and Supertech, and is not dramatically more expensive than multi-vehicle fluid.
Therefore, this isn't really a conversation to solve a specific problem, but I'm interested in potential benefits from a more "modern" fluid. I'd also like to reconcile an apparent contradiction:

Ford to my best knowledge considers Mercon V and Mercon LV incompatible, yet Valvoline lists its MaxLife fluid as suitable for both applications:

Given the age of our cars, a fluid with high mileage additives (seal conditioners, etc.) seems attractive. MaxLife is also a synthetic fluid while Mercon V is conventional.

A cursory search around the internet reveals mostly very positive reviews of MaxLife, too.

So who has actually used it in a 4R70W and can share some observations?

Meanwhile, I siphoned a cup of fluid out of my pan yesterday. It's quite dark though not burnt, and there aren't any visible particles. I flushed it maybe 12,000 miles ago, and I expected it to look better. :unsure:
Yes, ran it for about 8 years in my autos and never again....formula changed and i started "feeling' a different drive quality and then they lied on the test data to the point the state of California banned it for sale in the state. I run their Mercon V but I will not use any of the other products in anything I own... and here is why....a bit on a different order....

I have a 1965 Mustang with Ford/Warner designed T10 ultra-close ratio 4 speed. The car was my moms since new (special order) and been in our family since then. I learned to drive in this car as well, and in 1986 I bought it from them, did a ground up rebuild and have about 10k miles on the car to date. The tranny was rebuilt by guys in downtown Los Angeles who were very well known and been around since the 50’s, replacing the bushings and syncros as the gears, etc. were in really good shape. When I reinstalled it, I filled it with Valvoline 90w gear oil…. The same tried and true tested gear oil my dad (engineer and racer) used for decades and myself as well. The tranny always worked very well!

About 2 years ago, I needed to top off the tranny with about 1.5 ounces…. Was out of the 90w so made a trip to slep boys and bought a quart of Valvoline 75-90w gear oil, which stated on the label it was compatible with GL-4 spec oil (which is what our tranny’s call for). I also called Valvoline tech support and verified that the compatibility was a non-issue, which they affirmed.

Over the next 2 years I slowly began noticing that at times it was becoming increasingly difficult to downshift into 2nd gear… no grinding, just acting overly firm. As the tranny warmed up higher, this occurred in 1st gear as well. Finally got to the point where as soon a the tranny warmed up, it was difficult to downshift into 1st or 2nd gear without bringing the car to a complete stop.

Ok, so since I am old school, and still trouble shoot by seeing, listening and feeling, I checked out the tranny……shift linkage was dead on, clutch seemed good but I added a little more reach (1/4”) for it, gear oil look good, visually through fill hole- the internals looked good as well. Took her for a drive, and still the same.
At this point I’m sitting back in my chair giving this some deep thought since it doesn’t make any sense…… and I come the the conclusion that this didn’t start until after I added oil…… checked around and found that over 100 people online are griping about the same thing, most are dropping their tranny’s and rebuilding them finding excessive parts wear (bushings, synchro’s).

Although I am now thinking about pulling the tranny to see what’s going on inside, I just haven’t convinced myself that this is mechanical related….. it has to be chemical related especially since it appears to be temperature related.

So out of mere “Gut Instinct”, I did a little R&D and found Brad-Penn makes a GL-4 specific gear oil…. Called and spoke to an engineer… he was great and after going through everything, he also agreed that although there was nothing else to indicate, he agreed, the chemistry issue was a real potential…. and he offered me a free oil analysis.

I let “Betsy” sit for 1 month allowing all the oil and particulates to settle. I bought 4 quarts of BP GL-4 and dumped the oil…. The 1st 8 ounces I drained into a bottle for analysis…. This would also show the highest contamination but would give us the best idea of what was going on. I flushed the tranny with 1 quart of the GL4, then filled her up.

The oil analysis came back indicating early signs of bushing specific wear….. just what I thought was happening…. The Valvoline oil was reacting improperly and instead of transferring heat away, it was increasing the heat causing the bushings to swell and in essence being way too big forcing and sychro’s way out of alignment……. In short, what a way to destroy a tranny!!!!

With the BP GL4 oil in her, I took her out and immediately noticed a difference…even just the feel, vibrations, sound. I ran the freeway at 70+ mph, downshifting through the all the gears and can only describe it as “Silky-Smooth”.On my return trip I did the same thing, but when I exited the freeway and downshifted through the gears, I use no throttle- just merely pushing in the clutch and shifting the tranny….. same result….. absolutely “Silky Smooth”! Honestly the tranny has never ran quieter (although it was quiet before)……. And Valvoline gear oils will never touch any vehcicle I ever own again!

BTW, when I called the Valovine tech support line and advised them on what had happened, the 20 something young lady, reading the PC said I must have bought the wrong oil.... and I'm not kidding when I say this...she laughed at me literally! So much for consumer/product support.

Anyway, I hope this helps those in need!
The Maxlife is not a good choice for the 4r70. It is a much thinner viscosity, more in line with the MerconLV or DexronVI. It is a great fluid for many newer transmissions, but not really appropriate for the 4R70.
I will read up on the other posts and possibly elaborate a little more later (buttcrack of dawn here and I am NOT a morning person!) but I used it for a while. I stopped after I learned more about Ford's modern fluid lineup and realized it was equivalent with the newer, thinner Mercon LV (low viscosity, as Mike said) compared to the correct Mercon V.
The Maxlife is not a good choice for the 4r70. It is a much thinner viscosity, more in line with the MerconLV or DexronVI. It is a great fluid for many newer transmissions, but not really appropriate for the 4R70.

I have had this exact thought myself; however, think about it this way:

The original Mercon is closer in viscosity (index) to LV than to V. And originally these transmissions were designed for Mercon (sans V).
So as long as the anti-shudder additive package satisfies V requirements, which is important for our torque converters, then the lower viscosity shouldn't be an issue.

All this is pure amateur speculation of course...
OK, I'm partially taking back what I said...

While the original Mercon is closer to LV in viscosity index, it is essentially the same as V in viscosity. :unsure:
I don't mess with those multiple application fluids especially when working on other people's cars. In this day and age where every car has its own specific trans fluid and coolant I stick with exactly what is specified whenever possible. It isn't worth the potential trouble if you misread what specs they say their fluid meets. The last time I changed the fluid in our '97 I just used some Motorcraft Mercon V.
I just watched this video, and one thing did give me pause: the expression "suitable for use".

Apparently the additives manufacturer has three categories designating their additives' compatibility with car manufacturer specifications, e.g., Mercon V:
  • Approved
  • Meets requirement
  • Suitable for use

Going back to the Valvoline spec sheet I linked earlier, it uses the same suitable for use terminology. In other words, it's the lowest level of compatibility.
I've used castrol Mercon V for pretty much the entire time I've had my mn12.It's a synthetic oil, and lasts pretty well. I usually change it every 25k. It's usually still clean when I drain it. I use the old oil for cleaning parts for the next trans.
Mercon. Not mercon V. The static and dynamic properties are completely different. Mercon is "slipperyier" Than mercon V, which keeps the direct clutch from locking up cleanly, without slipping.
Mercon. Not mercon V.

Yes, understood.

But those two links above give some insight into the California situation, which was related to labeling MaxLife as Mercon in spite of differences in viscosity of the fresh product.

Viscosity of Mercon and Mercon V are essentially identical, so I figure the above info still applies.

Mercon V's differences from Mercon seem additive-related. Both are conventional oils. However, the concerns people expressed regarding MaxLife seemed more related to viscosity.

Also consider that our transmissions were originally designed for Mercon, which would work fine if it wasn't for heat-related degradation of friction modifiers. At least that's my entirely amateurish understanding of what I have read.
Mercon V was specifically designed for our transmissions, because of the design. The Castrol Mercon is synthetic. It needs to have a high static friction, which is not a requirement, or a property of mercon . C3's are completely different.
Not according to their own safety data sheet. It's mineral oil.

It's made up of a majority of refined crude oil aka petroleum distillates .. which has been chemically modified to make it "synthetic" oil.
Well, apparently not even Castrol thinks so, because Mercon V is not advertised as synthetic on their website nor on the bottle. LV and their multi-vehicle one are:

Screenshot_20240201_212840_Samsung Internet.jpgScreenshot_20240201_212849_Samsung Internet.jpgScreenshot_20240201_212900_Samsung Internet.jpg
I've used this for a combined mileage approaching 1 million miles, over 3 cars and a dozen worn out transmissions. I like it.
From what I remember ( it's been a long time since I bought Mercon V ) .. the Castrol was labeled as a synthetic blend and not fully synthetic.
I've used this for a combined mileage approaching 1 million miles, over 3 cars and a dozen worn out transmissions. I like it.

I hear you. I'm not disputing that it's a perfectly fine and Ford certified Mercon V.

All I'm pointing out is that nowhere in Castrol's own documents about their Mercon V will you read the word "synthetic"; yet the internet keeps saying that it is.
Eh, it is what it is. As long as it's spec'd for Mercon V, it's good enough for me. I stick with the Motorcraft stuff. It's the same price as the other brands in most cases (or less), so why not? :zshrug:

You mentioned earlier that you did use MaxLife for a while though. Any adverse effects?

Why not? Well, I'm thinking that a purpose made high mileage fluid may be more appropriate for our cars. Of course there's nothing wrong with Mercon V.
Well, it's a bit of a long story. Yes and no.

Put as succinctly as possible, I guess I can start off by saying that I put the most miles with that fluid on my old 96 Mark VIII. I got it with about 170,000 original miles. At 205,000, I swapped out the original 96 trans with the one from my father-in-law's 97 Sport, which had 40,000 fewer miles on it. The original Mark trans still worked fine, but it would occasionally "burp" when shifting into 4th gear - instead of a smooth application, it would sometimes catch abruptly. When the car was totaled at 50,000 miles later, everything with the drivetrain was pretty much status-quo.

That said, I got the 98 I'm driving now with a little over 130,000 on it, and it's coming up on 215,000. I had its transmission preemptively rebuilt at 208,000 because it was taking a few seconds to engage drive gears when cold during the winter months - the shop said the clutches were flaking and pretty worn, so it was well-timed. I've been using regular MercV on it though, which I first changed at 150k.
I've used castrol oils since the 70's. My bikes would destroy all the other oils. I just happened to drain some kendall oil into a mason jar, and it seperated into 3 layers. None of which was water, lol. That was after a 40 minute moto. I paid attention after that. FWIW, you can't use synthetic motor oil in anything with a wet clutch, as it's too slippery, the clutch will smoke under power. Hookup characteristics are critical for clutches.

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