Going through my owner's manual, for normal service, the fluid change interval is 150,000 miles. for "severe" service the interval is listed at 60,000 miles.

I've got 135,000 miles on the clock now and just changed it this weekend. With no indications that the vehicle was used under the "special operation conditions" listed before i bought it a year ago, by all accounts i changed it "early" (i have been trying to get to it for the last 30,000 miles, but life kept getting in the way).

based on the color of the fluid coming out, i can't help think that 150,000 is FAR too long under any conditions. The fluid was very dark with only a hint of red left.

Just my opinion, and if anyone were to ask my advice on the topic i'd say:
with the fluid being so easy to change (use a pump to add the new fluid), there is no reason to run the fluid 150,000 miles. the 60,000 interval is much more reasonable, IMO.

this comes from my experience with this vehicle and my explorer before it. when i changed the fluid in the explorer at 100,000 miles, the fluid was very dark as well. then when i i changed it at 160,000 miles, the fluid was still nice and red, despite all the heavy towing and off-roading i did with it.

i think with how the fluid looked, i'm going to run this fluid 20-30k miles, then change it out again. again, with it being so easy, it's easy to justify.

anyway, just some thoughts, in case anyone were contemplating changing the fluid in their transfer case.

 

Nice post. You have to wonder about the differentials too, even though many are permanent and never require changing out.

 

mine will get changed before too long. (I say that realizing that it took me a year to get the transfer case done)


I've never been a fan of "lubed for life" as I feel the life will be much longer if you change it out.


the rear has a drain plug, so that one will be easy, but the front one will require me to suck it out or break the seal (i'll just suck it out)

 

So what did ya put in for trans case fluid?

 

I hear you but at the same time, this is all engineered and tested, so sometimes you've just got to have faith and leave it alone.

 

i used what i had on hand, which was SuperTech Mercon/DexIII from walmart. Usually i would use a full synthetic, but i've been short on time so i just used what i had. Nothing wrong with the SuperTech, just like to use synthetics where i can.

no real disagreement, the only thing that bothers me is that the service guides stop at 150,000 miles, indicating (at least to me) that 150,000 is considered the life of the vehicle by the manufacturer. I like to keep them longer, if at all possible (usually into the 200k range barring unexpected deal-breaker type repairs)

 

Yeah, that's my concern as well.. When a manufacturer says it's maintenance free and is designed to last for the life of the vehicle, I always question what is their definition of "life of the vehicle". I'm sure their definition and a consumers definition is quite different on that part..

 

I'm gonna change fluid on my transmission in the near future, and was thinking I'd do the transfer case at the same time.

Can I use Mercon V in the transfer case? The manual says Mercon only, (not V), and Mercon V for the transmission of course.

I've heard that you can't put Mercon in a transmission that calls for Mercon V, but you CAN put Mercon V in a transmission that calls for Mercon, is the transfer case the same or should I really get Mercon (non V) for it?

 

While not stared specifically, mark's comment leads me to believe that mercon v might be a safer choice since it is tested and certified by ford.

https://www.ford-trucks.com/forums/1...+transfer+case



Interestingly enough, supertech mercon v is certified by ford, so it should be a safe bet.

 

So Mercon has been discontinued and Mercon V replaced it? Really weird that Ford specifies the non V for the transfer case in the factory shop manual... But it's not the first time Ford makes their factory manual confusing..

 

There is a TSB out there which dictates all Mercon applications should now be using only Mercon V.

 

Ok, that pretty much sums it up. I'll put some Mercon V in it.. No Motorcraft oil available here, but I'll get either Castrol, Valvoline or Mobil 1, whichever they have that can muster up the 17-18 bottles I need.

 

Here is the TSB.

 

Motorcraft Mercon V bottle states not to be used in transfer case.

 

Well, that may apply to different transfer cases? Isn't there some transfer cases that uses a "transfer case fluid"? Since the TSB says all applications which previously used Mercon now should use Mercon V, then the transfer cases which calls for Mercon should fall under that category...