2004 Expedition trans fluid and diff oil

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Sep 22, 2012
I just bought a 2004 Expedition XLT 4wd with 109k on the clock. I want to replace all the fluids asap but wanted to ask on BITOG first for suggestions. Manual states: Differential F and R- 75w90 Transfer Case- Mercon ATF Trans- Mercon V Does anyone have any experience with non Motorcraft fluids in this truck? The Motorcraft synthetic 75w90 gear oil is like $20+/qt! I have also read places that Ford now recommend 75w140 synthetic as back spec. I appreciate any help on this as I want to keep this truck a long time and I love the feeling after replacing all the nasty fluid with fresh blood! I am looking to avoid spending mega bucks for the motorcraft if possible. I have seen Havoline Mercon V on Amazon for 49.99 for a case of 12. Is this any good? I have also seen many 75w140 synthetic oils for 11-12/qt (ie. Mobil, Redline, Lucas). Thanks.
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I have used MC, Castrol, and Amsoil in my FX4 with good results and in my 1999 Expedition and F-150, I used M1 also with good results (in the differentials). Really any brand name oil that meets the specification for the differential should be fine. I do not think these things are very hard on gear oil like some of the other axles are. I have only used Motorcraft in the transmissions so I cannot speak towards any other brands.
when you replace atf make sure you replace the filter, better to do it now than later, i would not see any problem using your favorite brands of fluid
I have used both: Valvoline maxlife (walmart in gallons) and Mag1 (quarts from amazon prime) In Dex/Merc, and Toyota T-IV and WS applications. Both are full synthetic fluids and not expensive. In all of the applications they have both been superb fluids. Both say in their spec sheets they are recommended for Merc V and I would not hesitate to use either if I were you.
The manual States to only use mercon v fluid but no fluids that cover several types of fluids (like mobil 1 atf?) I will check the manual again.
Mobil 1 atf was reformulated a few years ago. It lost it's Toyota and Dexron VI recommendations, but it is now spec'd for Mercon V, so that is a very good option for you, too. https://mobiloil.com/en/automatic-transmission-fluid/synthetic-atf There are a lot of options that are superior to the dino motorcraft. If your Camry is an auto, the MaxLife or Mag1 would be great for it. Finding T-IV recommended fluids is a bit harder, and both of them are good for that.
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I have only used Castrol MERCON V in the past. It was fine- I am sure anything else meeting the spec will be fine also. Use a motorcraft filter for sure. I used a parts-house filter once, it did not fit well at all. As for the diffs, you can't go wrong with Mobil 1.
Did a few d/f on my 2002 2wd Explorer. It's rebuilt trans with 50k was starting to slip. Redline D4 really helped. I definitely recommend. I also put Redline 75w140 in the rear differential. Didn't drive it long after the diff fluid was changed, but no issues.
If your goal is the least expensive options that still meet the specs, then it's Maxlife ATF for the trans, any store brand Dex/Merc for the transfer case, and Valvoline white bottle 75W-90 gear oil for the diffs. I've looked at the PDSs for gear oil and the numbers for the Valvoline 75W-90 are on par or better than almost all the other brand name syns out there, and the price is much less. The reason that Ford back speced 75W-140 for their rear diffs was to combat customer complaints of whining (the diffs not the customers) at highway speeds. The 05 Mountaineer I had did this for 100k miles even with 75W-140 in there, but never caused any issues. Feel free to try the 75W-90 and see what happens.
I Changed out the diff fluids and the transfer case fluids. I used Mobil 1 75 W 90 in the front and Mobil 1 75 W 140 in the rear as well as the Havoline mErcon v in the transfer case. Old differeNtial fluid was absolutely nasty and the drain plugs were covered with a nice amount of magnetic goop. I'm so glad to have the fluids Out. Thanks
I bought some mobil 1 atf for a buck each at AZ. Can I use this in the expedition transmission? Some people say it HAS to be licensed mercon v only. M1 is mercon v equivalent. Should I be OK?
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