Maxlife for 35yo Ford C6

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C

Cubey

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It's highly probable that my 1985 E350 RV has it's original transmission fluid. Or if not, it's still probably 25-30 years old. It's still somewhat red, but it's definitely dark. No trans problems, amazingly. I have had it for a year/4k miles. Odometer has likely never rolled over, original 73k.

Since I'm doing a bit better financially this year and I just noticed its fluid condition, it's time to change it. I am planning to do it myself despite dreading it. I want to know that the filter has been replaced, the torque converter drained, and pan has been cleaned.

I don't trust any shops around here to do it properly and/or not to rip me off. The good, trustworthy transmission shop closed down a couple years ago, after about 50 years.

I am guessing that MaxLife is the best choice for it. $18/gal from Wartmart is hard to beat. There is conventional Valvoline ATF for $14/gal but I think the full synthetic Maxlife with the seal conditioners would be better for an aged transmission like this.

Thoughts?
 
Maxlife will be fine
smile.gif


Since your transmission doesn't have a drain plug, you may want to get an aftermarket pan that has a drain plug, so future ATF changes will be much easier
 
My concern with the MaxLife is that it's "thin" but holds up better. I'd look into a high-viscosity synthetic meeting the Mercon specs but MaxLife should be OK. I think in an RV, a synthetic like M1, Red Line or Amsoil would be a much better choice.
 
An '85 C6 calls for Mercon which was basically a Dexron II equivalent, So Maxlife would be a good suitable replacement!

Some C6 units perform better with good 'ole Type F....Especially if it's a little too soft?
 
Originally Posted by slacktide_bitog
Maxlife will be fine
smile.gif


Since your transmission doesn't have a drain plug, you may want to get an aftermarket pan that has a drain plug, so future ATF changes will be much easier


I am thinking that too, but the low priced ($30) steel ones with a drain plug are deeper and they lack a filter extender. I'd have to spend $160-200 (plus 10% tax) on a fancy aluminum one to get a pan with an extender.
 
Originally Posted by nthach
My concern with the MaxLife is that it's "thin" but holds up better. I'd look into a high-viscosity synthetic meeting the Mercon specs but MaxLife should be OK. I think in an RV, a synthetic like M1, Red Line or Amsoil would be a much better choice.


The dipstick calls for Dexron-II. Weird, I know. Did Ford not have "Mercon" yet in 85? It would be weird if someone changed the transmission dipstick.
 
Originally Posted by clinebarger
An '85 C6 calls for Mercon which was basically a Dexron II equivalent, So Maxlife would be a good suitable replacement!

Some C6 units perform better with good 'ole Type F....Especially if it's a little too soft?


They quit using Type F after 1979 I think. The dipstick flat out says to use Dexron-II.
 
Just me... But I'd run a Dex/Merc fluid in it....

That fluid meets Dexron II and Dexron III and Mercon...
 
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Originally Posted by nthach
My concern with the MaxLife is that it's "thin" but holds up better. I'd look into a high-viscosity synthetic meeting the Mercon specs but MaxLife should be OK. I think in an RV, a synthetic like M1, Red Line or Amsoil would be a much better choice.



Are you saying that Maxlife is not a synthetic like M1, RedLine, or Amsoil?
confused2.gif

[Linked Image]
 
Another vote here for Castrol Dex-Merc or maybe Castrol Mercon V if several drains are done, to include the torque converter (I think it has an accessible drain bolt on your engine).

Valvoline Maxlife is a Low Viscosity fluid, not at all adequate for older transmissions. It's not a magical fluid like people think it is and it should be used only to replace modern LV type of fluids.
You don't put 0W-20 in your engine if factory required 10W-40, why would you do that to an old transmission??? "Holds up better"??? Sure, but that is starting with improper low pressure lubrication!!!
 
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https://en.wikipedia.org/wiki/DEXRON

Dexron VI is of a slightly lower viscosity when new compared to the prior Dexron fluids
(a maximum of 6.4 cSt at 100 °C for Dexron VI and 7.5 cSt for Dexron III),
but the allowed viscosity loss from shearing of the ATF during use is lower for Dexron VI,
resulting in the same lowest allowed final viscosity for both Dexron III and VI (5.5 cSt) in test.[21]

In reality most of the DEXRON-III fluids typically sheared to about 4.2 cSt in use.
The lower, more stable viscosity improved pumping efficiency within the transmission
and fluid stability over life. Since Dexron VI is not allowed to thin out (lower its viscosity)
as much as Dexron III during use, it requires the use of higher-quality, more shear-stable (less prone to thinning while in use) formulations.

Built before 2006, most can use the new Dexron VI, but the older Dexron III is a safer and cheaper choice...
My Saturn SL2 is one of the exceptions,

https://www.walmart.com/ip/Valvoline-DEX-MERC-Automatic-Transmission-Fluid-1-Gallon/15125788

(Note that the Mobil 1 Delvac ATF is a cSt of 7.3)
 
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Yeah I'm with you... I just did two drain and refills on my lady's 1998 Camry. The car had Dexron III in it from the factory... That's what I just put back in there... Coastal Dex Merc in there. I would not put Dexron IV in that car... And it's been running just fine on the Coastal Dex Merc fluid.
 
Synthetic might be "better", as a general statement, but we still need to match the basic viscosity specs that the transmission was designed for.

From my readings, only AMSOIL makes a synthetic transmission fluid appropriate for normal (older) viscosity fluids.
They sell a version of that as LV too (they call it Fuel-Efficient), so they change the additives accordingly.
 
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What about this one? It says Dex2-3/Merc, but not Merc V or other "multi vehicle" use.

[Linked Image]
 
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Unless it's been replaced at one time with an aftermarket unit, your torque converter will have a drain plug. It can be a PITA to get the drain plug in the lowest position, but you will be able to get out another 4-5 quarts of old fluid by draining it. I changed the filter and fluid in my Navigator last weekend and refilled it with about 14 quarts, half of it with SuperTech, the other half was Valvoline.
 
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Originally Posted by Kruse
Unless it's been replaced at one time with an aftermarket unit, your torque converter will have a drain plug. It can be a PITA to get the drain plug in the lowest position, but you will be able to get out another 4-5 quarts of old fluid by draining it. I changed the filter and fluid in my Navigator last weekend and refilled it with about 14 quarts, half of it with SuperTech, the other half was Valvoline.


Supposedly, it's 7-8 quarts in these C6 torque converters, and only 3-4 in the pan. So TC draining is almost required.
 
Originally Posted by bbhero
Just me... But I'd run a Dex/Merc fluid in it....

That fluid meets Dexron II and Dexron III and Mercon...





Well, not just you. Me, too!
thumbsup2.gif


Castrol, ST, etc. I don't know about using the High Mileage ATF??? Not saying it is bad. Merely saying, IDK.

I even purchased Toyota OEM DIII for my 2002 4Runner. I have decided to only use what my transmissions were designed for and Drain and Fill every 30K.
 
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