New to me 2004 Expedition 5.4l Transfer Case fluid?

[wlk]

Hello all. I just bought an 04' Expedition, 181k miles, have been going through and changing fluids, everything so far has been in great shape as older couple had everything serviced at the local Ford dealer. I am wanting to change the transfer case fluid but have probably over-read everything and have confused myself which fluid to use. My original spec was Mercon in TC. I have read several posts and went to dealer for correct fluid. Dealer states Mercon V is new spec fluid but I have read not to use this several places- maybe old formulation (?) and to use Mercon LV several other places suggest.
I am new to Ford's, 1st I have ever bought and not had many 4x4's before. I am not brand specific but just looking for the correct fluid for this thing. Thanks

 

[GSCJR]

We have a great member @bdcardinal that can help with your question; Standby.

Mercon LV appears to be the current specification for those; Let's wait and see.

 

[bdcardinal]

The latest supercession from Ford will be Mercon LV. Mercon V was never approved for transfer cases unless specifically called for in the FSM.

 

[BlakeB]

FCSD Chemicals and Lubricants

Mercon LV

 

[wlk]

Perfect, thank you very much for your replies. I didn't think Mercon V was right and I'll grab some LV and call it a day.

 

[Snagglefoot]

Here is your owners manual recommendation: Mercon. The main thing is that basically it’s an ATF. Seems to me Mercon LV will will have a lower viscosity than regular Mercon. About 7 cSt for Mercon and 6 for Mercon LV. Not much difference.

 

[SoNic67]

Perfect, thank you very much for your replies. I didn't think Mercon V was right and I'll grab some LV and call it a day.

Bad choice. Mercon V was a normal viscosity fluid, like Mercon.
Now you are planning to get LV fluid... I guess you care more about gas mileage (0.5mpg or so ) than the life of that TC.
Next thing you know you are posting here upset that "Ford TC are crap, they fail"....
I have junked a Ford Explorer AWD, at 200k miles, with perfect TC and transmission. Used Castrol Mercon V in both.

 

[wlk]

Bad choice. Mercon V was a normal viscosity fluid, like Mercon.
Now you are planning to get LV fluid... I guess you care more about gas mileage (0.5mpg or so ) than the life of that TC.
Next thing you know you are posting here upset that "Ford TC are crap, they fail"....
I have junked a Ford Explorer AWD, at 200k miles, with perfect TC and transmission. Used Castrol Mercon V in both.

I asked for the correct fluid as Mercon is not available anymore. Read multiple places that Mercon V can and has damaged transfer cases and Ford put out to not use it in TC before. I asked if it got reformulated as it was a while ago. I never said boo about mpg's, don't care about them as it's a heavy vehicle that i am going to pull my camper with.

 

[bdcardinal]

I wouldn't worry about it. All of the new Super Dutys, even up to F-450 take LV and we pretty much never see any issues with them.

 

[ripcord]

Mercon is widely available, just not under the Motorcraft brand. Mercon is the essentially the same as Dexron III. Neither of those are licensed by Ford or GM, but every oil maker in the world still knows the formula. I think we can trust Valvoline or Castrol. They just can't put Mercon or Dexron III on the label due to the licensing technicality.

The problem with using Mercon V in transfer cases was supposedly it has something in it that dissolves the adhesives used to glue friction materials.

 

[SoNic67]

I asked for the correct fluid as Mercon is not available anymore. Read multiple places that Mercon V can and has damaged transfer cases and Ford put out to not use it in TC before. I asked if it got reformulated as it was a while ago. I never said boo about mpg's, don't care about them as it's a heavy vehicle that i am going to pull my camper with.

Castrol® Transmax™ DEX/MERC meets MERCON requirements.
Here is the datasheet: https://msdspds.castrol.com/bpglis/...3A1FD148025814500665523/$File/BPXE-ANM933.pdf

The problem with using Mercon V in transfer cases was supposedly it has something in it that dissolves the adhesives used to glue friction materials.

The AWD in my Explorer didn't use friction packs, it was a true differential with a sealed Vascous Coupler, so probably that's way it didn't matter.
I agree that there are plenty of fluids compatible with the older Mercon formulation and Castrol is definitely a brand that I trust.

All of the new Super Dutys, even up to F-450 take LV and we pretty much never see any issues with them.

I am not sure that's true. Even if those manuals say LV, it doesn't mean that the older TC's can take that too. Small internal changes might be made for the lower viscosity fluid.

 

[OVERKILL]

I used M1 ATF (plain-Jane Dex/Merc) in our 2002 t-case:

Mobil 1™ Synthetic ATF oil | Mobil™ Motor Oils

Discover how synthetic automatic transmission fluid like Mobil 1™ Synthetic ATF provides your SUV or car outstanding resistance to oil breakdown and deposits.

www.mobil.com

Performance-wise, it seemed to stay clean and actuation of the unit was quick even when extremely cold (when I'd often be putting it in 4HI).

I've also used the AMSOIL ATF, which seemed about the same.

Both are also great choices for your power steering fluid, as would really be any of the aftermarket synthetic ATF's that are D/M, depending on what you can get the best deal on.

 

[dogememe]

Valvoline Transfer Case Fluid

 

[stanlee]

Valvoline Transfer Case Fluid

This stuff is the truth. My transfer case was knocking as I came to a stop. Couldn't figure out from what until I put this in my Ford explorers transfer case. It is an acceptable replacement for Mercon LV.. That was about 100k miles ago and I change it every 20k miles. As mentioned Mercon V is thought to be responsible for grenading Ford transfer cases and per ford should not be used (it was spec'd for a short while when Mercon V first came out).

 

[4WD]

This stuff is the truth. My transfer case was knocking as I came to a stop. Couldn't figure out from what until I put this in my Ford explorers transfer case. It is an acceptable replacement for Mercon LV.. That was about 100k miles ago and I change it every 20k miles. As mentioned Mercon V is thought to be responsible for grenading Ford transfer cases and per ford should not be used (it was spec'd for a short while when Mercon V first came out).

There are a few dual licensed and single licensed + dual recommend Dex VI/MLV ATF’s … So if this is a replacement for one why not the other … ?

KV100 is 5.91 ?