Transfer Case Fluid Requirements
Is it possible that only Ford has placed this warning label on its Mercon V bottles?
If so, that only can add to the non-OEM customer's confusion.
Last year I finally discovered a long-time front end ailment. My hub needle bearing dried up and puked all over the inside of the hub, along the axle and into the locking hub. This problem had persisted for probably close to 2 years before I really focused on it and fixed it. The needles were jammed in the auto locking hub which effectively locking the axle and had been spinning for up to 2 years. I've had no issues with the transfer case and have not flushed the ATF in the transfer case since I bought it and put Mobil 1 in there.
Just my opinion and .02
As I was in a NAPA store the ATF that I looked at was not Motorcraft but I did not pay close enough attention to what it was exactly. The T-case fluid is ACDelco Auto-Trak ll #'s 10-4017 & 1#88900402. I mentions GM vehicles specifically but I don't know if they use New Process T-cases or not or if it even matters.
Don't know if that contributed to my BW 1356 transfer case tailshaft leak and the recurrence of the transfer case tailshaft leak after rebuild under warranty. And I don't know what ATF the converter put in the transfer case when he installed the transfer case in 2007. I only know that Mercon had been discontinued at that time, and Ford was recommending that Mercon V be used everywhere Mercon had previously been used...
So, I mention the fluid changes by Ford for the Transaxle. He says Yup, we been doing it for about a year. We got an bulletin from corporate. I say can I see the it? He says sure, we go in and pull up their bulletins from their corporate office and it says:
Discontinue the use of MERCON-V additive in all Ford Transfer Cases. Refer the customer to Ford (Motorcraft Part Number XL-12 Transfer Case Fluid). That was March 2013. DO NOT SUBSTITUTE AT THIS TIME.
Reference communication XXXXXXX, Inform Customers of the new requirements (it is now added to computer base archives for Ford Vehicles), Inform the customer you will be using Dexron II/III Equivalent Base Stock until delivery of Motorcraft XL-12 or equivalent. July 2013
We looked up my truck and it said ATTENTION IN RED LETTERS followed by: XL-12. So they updated their database.
The last communications was November 2013 stating a stock code for Jiffy Lube for ordering and will become available in early 2014.
So, while I had dismissed this, I went a head and had him change it too while I was there for $20.00
Better safe than sorry I guess.
He said he had heard nothing about the issue other than the fluid change. However, the first communication was marked "URGENT".
On the XL-12 Transfer Case Fluid bottle, Ford states:
"For use in transfer cases where MERCON® ATF was previously recommended. "
The confusion is understandable. Way back when Ford first introduced Mercon V, Ford cautioned everyone, saying that Mercon V may not be backward compatible with Mercon. Even our resident transmission expert, Mark Kovalsky, is on record numerous times in the archives of several forums stating emphatically do NOT use Mercon V in the 4R100, back in the days when he was working for Ford.
However, then, Ford did an about face (probably after sufficient field testing determined no detriment) and announced that Mercon V is indeed not only backwardly compatible with Mercon, it is in fact BETTER than Mercon for the applications that used to call for Mercon. And seemingly just to make sure that transmission shops didn't use Mercon in applications designed for Mercon V, Ford announced the sunset of Mercon licensing. Accordingly, Mark changed his recommendations (while still working for Ford) to suggest Mercon V for all Super Duty automatic transmission applications formerly calling for Mercon.
The idea that Mercon V is now appropriate for all applications calling for Mercon is where everyone gets tripped up... because in earlier model Superduties, the part time transfer cases (NV271 and NV273) call for Mercon fluid. Accordingly, people have put in Mercon V in the transfer cases. But this isn't what Ford recommends. Ford probably could have been clearer about this earlier on, but Ford appears to be making up for this lack of clarity by being really clear now:
On all Mercon V bottles, Ford states:
"Do not use in transfer cases where MERCON® ATF was previously recommended."
Beyond doing what you've already done, which is to read the bottle, unlike what the dealership personnel that you've dealt with appear to have done, an alternative way to confirm this is to look at an owners manual for a later model Super Duty, built after Ford ceased issuing the Mercon specification license to fluid formulators.
With the same model transfer case (NV271 and NV273), Ford puts in writing their recommendation that Super Duty owners use Motorcraft XL-12 Transfer Case Fluid in the transfer case.
Transfer Case Fluid in the transfer case. Makes sense to me!
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