Mercon V versus Transfer Case Fluid (XL-12)

[CarbonSteel]

As part of the fluid changes happening in the next few weeks, I stopped at my local Ford dealer to pickup some transfer case fluid and while I was there I thought that I would pickup a couple of bottles of Mercon V for the power steering fluid change as well.

As part of the initial "checkup", I had Ford change all of the drive train fluids at 13,300 miles. They used Mercon V in the transfer case (which I thought was a little strange at the time since there is a dedicated transfer case fluid--Part No. XL-12). I had read in different forums that ATF is often used in XFer cases, so at the time I did not ponder over it too long.

Today, when I went into the dealer and picked up the two fluids, I took the time to read the bottles. The XFer case bottle states "not to be used it in transmissions" (I assume there may be FM in the fluid), but the Mercon V bottle states "not to be used in XFer cases".

I am going to assume since my XFer case is not complaining or experiencing any problems that Mercon V did not cause any problems.

Anyone have some insight into this? It will not be a problem going forward as I have the XFer case fluid and will not be using Mercon V in it.

 

[Lakersguy]

The dealer messed up if they put Mercon V in the transfer case.

 

[dave1251]

Does your owner manual state to use Mercon V in the transfer case. That is what is stated on my owners manual and we almost have the exact same pickup.

 

[CarbonSteel]

Originally Posted By: dave1251
Does your owner manual state to use Mercon V in the transfer case. That is what is stated on my owners manual and we almost have the exact same pickup.

No; it states:

Code:


Item Capacity Ford part name or equivalent Ford part number/Ford specification

Transfer case fluid 1.6 quarts (1.5L)^5 Motorcraft Transfer Case Fluid XL-12/—

(4X4/AWD)



^5 Service refill capacity is determined by filling the transfer case to the bottom of the filler hole with the vehicle on a level surface.


I know in reading the F-150 forums there is a fair amount of confusion of what fluid should be used in which XFer case. I believe there was no harm done (at least as near as I can tell--the XFer case is working properly with no noises or problems), but I will use the XL-12 this time.

 

[dave1251]

Originally Posted By: 2010_FX4
Originally Posted By: dave1251
Does your owner manual state to use Mercon V in the transfer case. That is what is stated on my owners manual and we almost have the exact same pickup.

No; it states:

Code:


Item Capacity Ford part name or equivalent Ford part number/Ford specification

Transfer case fluid 1.6 quarts (1.5L)^5 Motorcraft Transfer Case Fluid XL-12/—

(4X4/AWD)



^5 Service refill capacity is determined by filling the transfer case to the bottom of the filler hole with the vehicle on a level surface.


I know in reading the F-150 forums there is a fair amount of confusion of what fluid should be used in which XFer case. I believe there was no harm done (at least as near as I can tell--the XFer case is working properly with no noises or problems), but I will use the XL-12 this time.


I would recommend just going this route to CYA. You have quite a bit of warranty remaining your Truck.

 

[bdcardinal]

I think at one point the owners manuals stated to use Mercon V, but there was a running change to XL-12. There is a lot of confusion even at the dealer level because some techs refuse to open up their minds to new knowledge. That being said, I stock the correct fluid and we follow the latest application charts and use the FSM to make sure the correct fuild at least gets handed out on the parts end.

 

[Roadkingnc]

The mercon v can cause the glue to fail that holds the fiber clutch to the steel backing, water will have the same effect

 

[CarbonSteel]

Originally Posted By: Roadkingnc
The mercon v can cause the glue to fail that holds the fiber clutch to the steel backing, water will have the same effect

Well...I hope not; it has been in there for 55K+. If it is going to cause a problem it needs to happen in the next 50K so that it is covered by the warranty

 

[Jim Allen]

Well, I'm running Royal Purple Synchromax in mine. It's a manually shifted, chain drive, part-time t-case with no special lubricant requirements. Unless you have AWD or a full-time unit, chain drive, part-time t-cases are not picky. Their design hasn't changed much in 30 years.

 

[mechtech2]

Originally Posted By: Jim Allen
Well, I'm running Royal Purple Synchromax in mine. It's a manually shifted, chain drive, part-time t-case with no special lubricant requirements. Unless you have AWD or a full-time unit, chain drive, part-time t-cases are not picky. Their design hasn't changed much in 30 years.



This seems to be a good grasp of the situation.

 

[buck91]

Zombie post.

Does anyone know what the xl-12 stuff is? Would i be better than M1/Amsoil ATF or just select the most affordable?