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Thread: Transfer case fluid change,differentials oil change Reply to Thread
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  Topic Review (Newest First)
07-14-2018 10:14 AM
losfinch Hey thanks, that was a great explanation since I've never seen the internals of our transfer case.
07-12-2018 03:43 PM
klhansen
Quote:
Originally Posted by losfinch View Post
I run with my hubs locked all year long and only unlock them when I'm going to be on a trip over 250 miles out on paved highway. I have 335,000 miles on my original transfer case. Im either having a mind-block or missing something but why would simply having the hubs locked be abusing your transfer case? I just manually shift the transfer case in and out of four wheel drive as I need it. I've always assumed that while the transfer case is not shifted into four wheel drive that my transfer case is not doing anything but going along for the ride....not "turning all winter long" like you mentioned. I'm not sure if I'm communicating this correctly so I hope I'm not sounding argumentative but rather trying to understand better. Thanks.
When the hubs are locked, the front output shaft of the t-case is being turned continuously by the front driveshaft, whether in 4x4 or not. The shift mechanism is in the top portion of the gearcase and when in 2WD, the upper chain sprocket is disengaged and it, the chain, lower sprocket, front output shaft and front driveshaft don't rotate.
I suppose "abused" was kind of a strong word to use, but with hubs unlocked, and in 2WD, there's less moving in the t-case, and less wear occuring. Granted the chain and sprockets aren't loaded, so there's less wear than in 4WD.
I guess what I was saying was that my lube choice hasn't caused issues even with the additional moving parts when hubs are locked in. Most guys with 4WD in less severe conditions (Ice, snow, etc.) likely run with hubs unlocked, especially those with auto hubs.
I wouldn't worry about your t-case.
07-11-2018 10:42 PM
losfinch
Quote:
Originally Posted by klhansen View Post
I'm at 215k miles, and run all winter with the hubs locked in, so my t-case gets abused a bit, turning all winter long whether in 4x4 or not, and it hasn't grenaded on me yet.
I run with my hubs locked all year long and only unlock them when I'm going to be on a trip over 250 miles out on paved highway. I have 335,000 miles on my original transfer case. Im either having a mind-block or missing something but why would simply having the hubs locked be abusing your transfer case? I just manually shift the transfer case in and out of four wheel drive as I need it. I've always assumed that while the transfer case is not shifted into four wheel drive that my transfer case is not doing anything but going along for the ride....not "turning all winter long" like you mentioned. I'm not sure if I'm communicating this correctly so I hope I'm not sounding argumentative but rather trying to understand better. Thanks.
07-11-2018 08:40 PM
fyrtygr Thx...
07-11-2018 04:13 PM
klhansen I just changed my tranny and t-case and used Mobil 1 Syn ATF (again). I'm at 215k miles, and run all winter with the hubs locked in, so my t-case gets abused a bit, turning all winter long whether in 4x4 or not, and it hasn't grenaded on me yet. I'm personally not worried about using a "non-approved" fluid.
But you could go by Ford's recommendation. They seem to change fluid specs as often as we change our underwear.
07-11-2018 02:32 PM
79jasper Still synthetic atf.
Or just get the tcase stuff from ford.

Sent from my SM-G892A using Tapatalk
07-11-2018 02:04 PM
fyrtygr
Quote:
Originally Posted by SmokeyWren View Post
Quote:
Originally Posted by bigb View Post
I am confused as to why the chart says synthetic but my owners manual says "Premium". They contradict each other.[IMG class=inlineimg]https://www.thedieselstop.com/forums/images/smilies/read.gif[/IMG]
Yes, but your Owner's Guide is 9 years old. The chart on the website is dated 6/20/2010. Apparently Ford engineers learned something during those 9 years.
So to ask in 2018....
What's best for the transfer case?
11-22-2010 09:19 PM
Demoh Speaking of wrong fluids for diffs, I was wondering about some of mine. For the sake of simplicity ive been changing all of my diffs with synthetic 75w140. thats 1 D50, a sterling, and a ford 8.8 in a car. The 8.8 gets the snot beat out of it and also havent added any friction modifier (a little chatter, but I prefer a firmer grab of the clutches) and havent had any problems at all in any of my axles.

Do any of you guys foresee any problems or should I take this post to pirate to get flamed there?
11-22-2010 07:31 PM
bigb Just changed it to synthetic 75/90. Thanks for your input.
11-22-2010 07:27 PM
SmokeyWren
Quote:
Originally Posted by bigb View Post
I am confused as to why the chart says synthetic but my owners manual says "Premium". They contradict each other.
Yes, but your Owner's Guide is 9 years old. The chart on the website is dated 6/20/2010. Apparently Ford engineers learned something during those 9 years.



11-22-2010 05:26 PM
bigb Yes, I see the chart says that. I am confused as to why the chart says synthetic but my owners manual says "Premium". They contradict each other.
11-22-2010 01:39 PM
SmokeyWren
Quote:
Originally Posted by bigb View Post
I just changed it with 80/90 rear axle lube, did I mess up?
That chart says your Dana 60 front axle in a 2002 needs SAE 75w90 synthetic rear axle lube. 2003-up Dana 60 front axles need 80w90 Premium rear axle lube (which I assume is dino and not synthetic). If the 80w90 you used is synthetic, then you're probably good tp go. But if it is dino juice, then I'd change it again and use the right stuff this time.



11-22-2010 01:03 PM
bigb
Quote:
Originally Posted by SmokeyWren View Post
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.fcsdchemicalsandlubricant...oduct=Transfer Case Fluid&category=Transmission Fluid

Sorry to drag up an old post, the quick reference chart you linked shows my 02 F350 taking 75/90 synthetic rear axle lube, and my owners manual says it takes 75/90 premium 4 wheel drive lube. I just changed it with 80/90 rear axle lube, did I mess up?
08-10-2010 08:28 PM
lance1955 Ive been running the mobile syn ATF for 7 years in my T-case. No problems. I change it once a year.
08-10-2010 07:57 PM
klhansen Not a peep from Exxon Mobil yet. I'll be sure and post their response when and if it arrives.
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