“Best” fluid for Transfer Case in 2016 Ford F-250

[Creekside]

The fluid in my transfer case is black again with roughly 20k miles since the last change. I’m using Mercon LV now. I’m not totally up on transfer case fluids and I was wondering if there’s a more robust alternative to the LV ATF or if I should stick with that?

Years ago I had one rebuilt in an 80s F250 behind a C-6 and the builder specified John Deere Hygard and only that. He said it held up much better than ATF in the chain drives. That truck is still running around town daily today. Not implying that Hygard is good for this unit but it did get me thinking about if I’m doing the best I can with LV.

 

[ripcord]

Mobil 1 and Valvoline both sell full synthetic versions of LV ATF that are Mercon LV compatible.

 

[MNgopher]

FYI - an old SSM on Mercon LV Fluid:

SPECIAL SERVICE MESSAGES
MERCON LV FLUID COLOR
VEHICLES, EQUIPPED WITH AUTOMATIC TRANSMISSION FACTORY FILLED WITH MERCON LV FLUID (PART # XT-10-QLV), MAY EXHIBIT DARK COLORED TRANS FLUID THAT MAY LOOK BURNT IN APPEARANCE. THIS IS A NORMAL CHARACTERISTIC OF THIS FLUID AND WILL NOT AFFECT TRANSMISSION FUNCTION OR DURABILITY. THE MERCON LV FLUID IS A DEEP RED COLOR, COMPARED TO CONVENTIONAL MERCON V BRIGHT RED FLUID, AND THE COLOR NATURALLY DARKENS AT RELATIVELY LOW MILEAGE. IN SOME CASES, THE FLUID MAY APPEAR TO HAVE A GREEN TINT DUE TO DYE USED TO CHECK FOR LEAKS AT THE ASSEMBLY PLANT. TRANS FLUID COLOR SHOULD NOT BE USED AS SOLE INDICATOR FOR TRANSMISSION REPAIRS. REFER TO THE CORRECT VEHICLE AND MODEL YEAR WORKSHOP MANUAL AND/OR MAINTENANCE GUIDE FOR DIAGNOSTICS, REPAIRS, AND/OR SCHEDULED MAINTENANCE.
EFFECTIVE DATE: 12/08/2009

I would not use color as the sole indicator that the fluid is bad...

 

[D60]

Seriously, watch above ^

Pretty sure I put basic Dex/Merc or Maxlife in my '11 Superduty. If you don't have automatic engagement or clutches I say any ATF will work.

If someone can cite specifics internal to the 'case that would dispute this and require LV, I'm all ears. Not just "Ford says"

 

[Creekside]

FYI - an old SSM on Mercon LV Fluid:

SPECIAL SERVICE MESSAGES
MERCON LV FLUID COLOR
VEHICLES, EQUIPPED WITH AUTOMATIC TRANSMISSION FACTORY FILLED WITH MERCON LV FLUID (PART # XT-10-QLV), MAY EXHIBIT DARK COLORED TRANS FLUID THAT MAY LOOK BURNT IN APPEARANCE. THIS IS A NORMAL CHARACTERISTIC OF THIS FLUID AND WILL NOT AFFECT TRANSMISSION FUNCTION OR DURABILITY. THE MERCON LV FLUID IS A DEEP RED COLOR, COMPARED TO CONVENTIONAL MERCON V BRIGHT RED FLUID, AND THE COLOR NATURALLY DARKENS AT RELATIVELY LOW MILEAGE. IN SOME CASES, THE FLUID MAY APPEAR TO HAVE A GREEN TINT DUE TO DYE USED TO CHECK FOR LEAKS AT THE ASSEMBLY PLANT. TRANS FLUID COLOR SHOULD NOT BE USED AS SOLE INDICATOR FOR TRANSMISSION REPAIRS. REFER TO THE CORRECT VEHICLE AND MODEL YEAR WORKSHOP MANUAL AND/OR MAINTENANCE GUIDE FOR DIAGNOSTICS, REPAIRS, AND/OR SCHEDULED MAINTENANCE.
EFFECTIVE DATE: 12/08/2009

I would not use color as the sole indicator that the fluid is bad...

That’s interesting thank you for posting this. I did my transmission fluid and filter on Thursday and noticed that it was darker than I would’ve expected. I just assumed it was due to towing and probably old fluid that was mixed with new on my first fluid drain and fill.

 

[Creekside]

Seriously, watch above ^

Pretty sure I put basic Dex/Merc or Maxlife in my '11 Superduty. If you don't have automatic engagement or clutches I say any ATF will work.

If someone can cite specifics internal to the 'case that would dispute this and require LV, I'm all ears. Not just "Ford says"

That’s about the color of my current t case fluid. I’ll probably leave it alone for now based on these comments.

 

[D60]

Actually I think I put this in my '11 because I got it for .88/qt WAY WAY back when TSC was clearing it

edit: this stuff is also rated for GM's AutoTrak II for those who hate proprietary fluids as much as I do....

 

[SC Maintenance]

Is Mercon LV the spec? I thought the "LV" meant low viscosity? I had issues with my Nissan transfer cases not shifting well when Maxlife dropped their viscosity a bit.

If its an old school transfer case - no clutches - going black in a transfer case is pretty odd. There is nothing to contaminate it - so would that indicate it is getting hot?

 

[Creekside]

Is Mercon LV the spec? I thought the "LV" meant low viscosity? I had issues with my Nissan transfer cases not shifting well when Maxlife dropped their viscosity a bit.

If its an old school transfer case - no clutches - going black in a transfer case is pretty odd. There is nothing to contaminate it - so would that indicate it is getting hot?

I’m pretty sure it originally called for XL-12 fluid but when I went to the dealer they said LV based off vin. I don’t know if it has clutches, I believe it’s a shift on the fly system but I’ve never used it that way. It has a knob on the dash to select 2H 4H or 4L.

 

[ripcord]

The XL-12 fluid was rumored by the interwebs to be regular old Mercon, AKA Dexron III. Supposedly, there was something in the original formulation of Mercon V that de-laminated the clutches in some of the older transfer cases, so after Ford stopped licensing plain Mercon, they came up with the XL-12 designation to continue selling Mercon for transfer cases that originally spec'ed Mercon.

Whether or not any of that is true, I haven't been able to find solid proof.

 

[zrxkawboy]

I would use a robust synthetic ATF, such as Mobil 1, etc.

 

[Vegasguy]

BG Syncro-Shift

 

[D60]

The XL-12 fluid was rumored by the interwebs to be regular old Mercon, AKA Dexron III. Supposedly, there was something in the original formulation of Mercon V that de-laminated the clutches in some of the older transfer cases, so after Ford stopped licensing plain Mercon, they came up with the XL-12 designation to continue selling Mercon for transfer cases that originally spec'ed Mercon.

Whether or not any of that is true, I haven't been able to find solid proof.

It makes A LOT of sense and seems to correspond with the FTM vid (although to be fair he never suggests XL-12 is any particular thing).

Regardless, a basic chain-driven, part-time, driver-selectable case shouldn't need anything more than Dex/Merc like they used since ~1980 (immediately after the NP205/203 were obsoleted). In these cases the fluid does nothing but provide lubrication for bearings and shift forks.

Many of these cases will even live surprisingly long if their tiny eccentric oil pumps fail solely from splash lubrication. Owners of BW1356s figured that out I repaired my share of BW1356 pump arms (same concept as GM pump rub except GM did a bunch of "pump arms" trying in vain to prevent the same problem)

 

[johnmyster]

Dex III and change more often.

Valvoline has a "Multi Vehicle" Import ATF that is full syn and a little thicker than MaxLife, if you prefer a FS lube. ATF+4 also fits the bill.

 

[brandon9715]

I don't think the transfer cases care too much. Since yours is like mine and has no clutches (no 4A), any LV ATF is probably fine. I changed my fluid to Amsoil LV ATF at 110,000 and have driven a year on it with no issues. I might change it again in a couple years, I might not. Transfer cases are not hard on fluids.

 

[oilboy123]

Dito Amsoil LV
Not cheap, but I believe one of best.

 

[ford250]

Redline D6 in mine Works perfect

 

[FusilliJerry]

Have the same question for an NP242 chain drive. Consensus across the internet was that cheap ATF would "mist" out of the breather and was not ideal and that New Process/Venture specified 5w30 motor oil. Doesn't seem like the ideal fluid either. My searches through the forums seemed to suggest Redline Power Steering Fluid could be ideal as it has the same viscosity as Dex III and a lot of zinc and the characteristics of a MTF.

I'd love to hear from @MolaKule, thoughts on what fluid characteristics might be ideal for chain driven transfer cases.

 

[D60]

Have the same question for an NP242 chain drive. Consensus across the internet was that cheap ATF would "mist" out of the breather and was not ideal and that New Process/Venture specified 5w30 motor oil. Doesn't seem like the ideal fluid either. My searches through the forums seemed to suggest Redline Power Steering Fluid could be ideal as it has the same viscosity as Dex III and a lot of zinc and the characteristics of a MTF.

I'd love to hear from @MolaKule, thoughts on what fluid characteristics might be ideal for chain driven transfer cases.

I'm not aware of NP242 issues but the GMT800 NP261 would inexplicably boil or lose its fluid. VERY common to pull the drain plug and get a drip of black (nasty/burnt) fluid and that's it.

I replaced with 5W20 in our '02 Silverado and had ZERO problems for many miles. I of course opened it up to see if any damage was done from lack of fluid and installed the MA pump rub kit.

As I understand it NP/NV didn't make the reco of motor oil but rather "aftermarket" orgs like ATSG etc. I may very well be mistaken there, though.

The optional full-time NP246 (which called for AutoTrak II) did NOT have this problem. I've been into both and don't know why the 261 (manual shift) and 263 (electric shift) would boil (or perhaps mist?) it's fluid and the 246 would not.

I mean they're built somewhat differently but the 261 is very similar to a ubiquitous 231 or BW1356 -- basically a simple, part-time t-case

 

[MolaKule]

Have the same question for an NP242 chain drive. Consensus across the internet was that cheap ATF would "mist" out of the breather and was not ideal and that New Process/Venture specified 5w30 motor oil. Doesn't seem like the ideal fluid either. My searches through the forums seemed to suggest Redline Power Steering Fluid could be ideal as it has the same viscosity as Dex III and a lot of zinc and the characteristics of a MTF.

I'd love to hear from @MolaKule, thoughts on what fluid characteristics might be ideal for chain driven transfer cases.

I would propose that either HPL Manual Transmission Life 75W75 @7.1 cSt or the Redline Power Steering Fluid would provide the needed wear protection.