Anyone know when you should change the fluid in the transfer case? I have 35,000 miles on my truck and just had the auto transmission flushed along with the front and rear differential fluid changed. I never even thought about the transfer case.

 

Believe it or not, Ford's normal recommended change interval for the t-case is 150,000 miles. If the truck is used primarily off road or for trailer tow, that is reduced to 60,000 miles.

Personally, I would change it more often than those recommendations. It's easy and really cheap since the case only holds 1.25 quarts.

 

I change mine every 30,000 miles, along with transmission fluid and differential lube

 

So you put the same atf in the tranny as you do in the t-case? what about the rear diff?
98 Ranger, 3L, 4x4 5speed

 

Mercon 5 (96 and newer) for both automatic trannys and transfer cases, I use 80w90 gear oil for diffs. I think you have to use a friction moifier in the rear diff if your truck came with a "traction lok" rear end.

 

negative.....both my owners manual and Chiltons manual says to use Mercron in the t-case.....

 

Never herd of Mercron, did you mean mercon? That's the same as mercon 5 unless you talkin bout mercon-dexron, which is for chevys or older model fords...

 

yea Mercon.......

Chilton says that the manufacture recommends changing the t-case fluid every 60,000 miles....don't doubt ya Bob, just saying.....i actually believe Bob over a Chilton...is that bad

Chilton also says:
when i changed mine last weekend, O'Reilly had the Mercon fluid...

 

Maurice how much is that stuff goin for at Oreillys? What brand was it? We only sell Valvoline and they are proud of that stuff, $3.99 a freakin quart!!

 

Mercon and Mercon V are the same now, any older transmission that takes Mercon Ford is saying can take Mercon V now too. I read something about it somewhere.

Besides the point Mercon V is perfectly fine to use in the Tcase. 95k miles on mine no issues and that is what i used. its been changed 3-4 times now. I change it whenever I feel like it.

 

it was Valvoline......i paid $2 a quart for it......

 

I think what you meant to say is that Mercon V is an acceptable replacement for Mercon, but NEVER the other way around. As I understand it, versions of Mercon less than version 5 are no longer being manufactured, so any of this stuff you find is old .

 

i did mine at 50k and plan to do it again at around 75k or 100k
like bob said it only holds 1.25q thats a very cheap flush. not worth waiting

 

ford is getting rid of reg mercon aka mercon III .... mercon V is is going to be the replacement fluid for mercon III fluid requirements ... and when that happens ford is coming out with a special fluid for tcases ... just fyi everyone :)

edit: and to answer the question i would do it every 30k ... i have seen ford trucks with 15 to 20k and the tcase fluid looks like engine oil ... i do mine every 15k, but i did my 30k at 15k as well lol

 

Is there a drain plug for the t-case?
Is there a walk through or pictures anywhere?