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2000 excursion 7.3 4wd.automatic. what fluid/additives and how much for changing tranfer case oil. also what oil / additives for diffs..do they take regular 80-90 wt and posi additive.also how much. thanks:icon_wink:
 

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the T-case takes regular old Mercon III, about 3-4 quarts

XY-90-GL in the front (SAE 90) in the front, 3.8 pints

XY-75W140-QL (synthetic)in the rear 6.5-6.9 pints, plus 2 XL-3 4oz modifiers in the rear in you have a limited slip

Sorry for the pints-its how my book lists fluids
 

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Transfer case: 2 quarts Motorcraft Transfer Case Fluid.

Rear axle: 6.9 pints 75w140 synthetic. Pay attention: that's SYNTHETIC gear lube.

Front axle: Your Owner's Guide calls for 3.8 pints 75w90 synthetic axle lube. The latest workshop manual published in 2003 for 2000 Excursion says SAE 90 Premium Rear Axle Lubricant.

The current quick reference chart for differential lube used by Ford techs is at:
Motorcraft quick reference chart for axle lubes

Since the quick reference chart is current, it may be different than old printed manuals from several years ago. I can't read upside down, so I've learned to print out the chart and then I can read it.

Transfer case lube changed a few years ago. Your Owner's Guide says to use MERCON, but MERCON is no longer available, and you cannot use MERCON V. So you have to use the new stuff Ford developed specifically for transfer cases - Mortorcraft Transfer Case fluid: http://www.fcsdchemicalsandlubricants.com/Main/product.asp?product=Transfer Case Fluid&category=Transmission Fluid
 

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Transfer case: 2 quarts MERCON V ATF

Rear axle: 6.9 pints 75w140 synthetic. Pay attention: that's SYNTHETIC gear lube.

Front axle: Your Owner's Guide calls for 3.8 pints 75w90 synthetic axle lube. The latest workshop manual published in 2003 for 2000 Excursion says SAE 90 Premium Rear Axle Lubricant.
They don't make a 75-140 that's not synthetic. And you don't need Mercon V ATF or SAE 90 (Ford just consolidated their fluids). Use Mercon III and 75-90 synthetic.
 

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Discussion Starter #5
i have synthetic 90wt.. good for front .. but looked at mercon V atf at store . it says on back "not for use in transfer case".. have to find some 75w140 syn.. is all 75w140 synthetic??
 

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All 75-140 will be syn. Try the Royal Purple. You don't need to add the friction modifier because it's already in it at the perfect amount.
 

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but looked at mercon V atf at store . it says on back "not for use in transfer case".
I have Mobil 1 ATF in my manual transmission and transfer case.
 

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but looked at mercon V atf at store . it says on back "not for use in transfer case"
What brand oil was it? The t-case in my older trucks used 90 Wt gear oil, but this one says ATF. My first change I used Mobil 1 ATF which was listed as Mercon. On the second change, the Mobil 1 ATF was now rated Mercon V, which is what I used.

Ford recently came out with "Transfer Case Fluid" see: Transfer Case Fluid, but I haven't been able to figure out exactly what it is. It's called for in the latest Superdutys starting in the '08 models, but if you look at your owner's manual, it will call for Mercon ATF in your t-case. Mercon V should be just fine. Ford says that Mercon V is OK for use in units that call for Mercon. MERCON® V Automatic Transmission and Power Steering Fluid

BTW, there never was Mercon III, but I believe plain ol Mercon was 'double branded' as Dexron III, which probably leads to confusion.
 

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Ford says that Mercon V is OK for use in units that call for Mercon. MERCON® V Automatic Transmission and Power Steering Fluid
Kevin, read that again and you'll see it says "Do not use ... in transfer cases."

So you can use the old MERCON but not the current MERCON V in transfer cases. Since the old MERCON is no longer available from legitimate manufacturers, use the new transfer case stuff. It's made of "PETROLEUM DISTILLATES
HYDROTREATED HEAVY PARAFFINIC LUBRICATING OILS (PETROLEUM). The Ford spec is ESP-M2C166-H. I don't know how to find the details of a Ford spec, but I'll bet you do. ;)

BTW, I found about about MERCON V not being useable in transfer cases a few weeks ago, but this old thread was before that. So notice I edited my earlier reply.
 

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I wonder why.. I've always just put atf in my transfer cases... alot of guys I know in the offroad world do the same.
 

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Smokeys right my manual calls for mercon (and they dont make it any more) and Ive been running mobile syn atf since 1st service. And have been ever since. No problems. But I service it every year. Overkill I guess, but a lot cheaper than a used new one if you get my drift :)
 

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I wonder why.. I've always just put atf in my transfer cases... alot of guys I know in the offroad world do the same.
Ford stopped the manufacturing of MERCON ATF by anybody a few years ago. MERCON ATF was fine in transfer cases, power steering pumps, automagic trannies, and the ZF manual trannies. MERCON V replaced MERCON for use in automatic trannies, but it's not good for transfer cases. So Ford had to come up with another lube for the transfer cases.
 

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... Ive been running mobile syn atf since 1st service. And have been ever since. No problems.
ExxonMobile changed Mobil 1 ATF to MERCON V about the same time Ford stopped the manufacture of MERCON. So if you buy fresh Mobil 1 ATF and read the label carefully, you'll see it's now MERCON V. It's fine for use in our 4R100 trannies, but not in our transfer cases.
 

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Royal Purple or Redline 75/140 for the rear( no friction additive needed)

75/90 for the front, either dino or synthetic

Mobil 1 for the transfer case

It doesn't get any easier.....

You can find all of them at the local auto parts...
 

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Kevin, read that again and you'll see it says "Do not use ... in transfer cases."
HMM, , you're right, Smokey, but Mobil 1 Synthetic ATF says on the bottle, "Also suitable for use in automatic transmissions for the following applications: .....Ford Mercon, Mercon V, Mercon LV...."
To me that means it's equivalent to Mercon, which was what Ford called for in my t-case as well as an automatic tranny for my year model.

I have a suspicion that Ford's "Transfer Case Fluid" may be the old Mercon, but that's just a guess. Maybe they rebottled their old Mercon stock and remarketed it. :icon_rolleyes: Ford doesn't say why not to use Mercon V in t-cases. I can't see what would make a t-case self destruct with Mercon V in it, as there aren't any synchronizers, friction clutches or similar things like you'd find in an auto tranny, just gears, bearings, and a chain. :shrug03:

I just put the question to Exxon Mobil thru their Mobil 1 website. We'll see what they say.
 

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Yes Kevin, please let us know what they say. I have had Mobil 1 ATF in my transfer case now for two years.
 

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Not a peep from Exxon Mobil yet. I'll be sure and post their response when and if it arrives.
 

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Ive been running the mobile syn ATF for 7 years in my T-case. No problems. I change it once a year.
 
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