Transfer Case fluid

[kumaxlt]

Is it OK to use Mercon V in the transfer case or should I use the DextronIII/Mercon? I read a few threads where some people did put in the Mercon V only to change it out for the Mercon/DextronIII.

I have a 1999 V6 SOHC 4WD

 

[IZwack]

I dunno about the specifics between the two but i do know that "V" is purely syn where as Mercon is not... so maybe one of the characteristics is that "V" is less viscous..

I usually sway towards DexronIII/Mercon as it is usually cheaper I mean the "ProLine" brand (cheapest of em all since i change the fluid quite often) is like less than $2.00 a bottle.

But I think MerconV should be fine in the transfer case... i've even ran gear oil in there for a few hundred miles (accidentally.. the syn "Royal Purple" brand).

 

[exploded99]

My understanding is that the Mercon V is a more advanced fluid than Mercon III - better performance, does not foam as much, better oxidation resistance, etc. If you look up mercon v on the net you will see some tech specs for many manufacturers.

Mercon V is fine. But you might consider using Mobil1 full synthetic in your transfer case. It exceeds Mercon V specs if I recall correctly, and tho its more expensive, you don't use very much in the transfer case anyway.

 

[Lee S.]

I've asked this question before and the response I got was to stick with regular Mercon in the transfer case.

http://www.explorerforum.com/forums/showthread.php?t=100074

There must be a reason that Ford specs call for Mercon the TC and Mercon V in the tranny... Maybe it was just the cost difference between the two to save them some money... I don't think I'd take a chance with my TC though.

 

[Runnin'OnEmpty]

The Mercon V has added friction modifiers, mainly to prevent the potential clutch shudder that some earlier Ford trans were plagued with. It's also more oxidation stable.

It'll work fine in transfer cases, but there's no need for it, since the TCs' don't have clutches and generate much less heat than trans do. It's not a 'better' ATF than Mercon/Dexron III, just has different specs.

 

[IZwack]

since the TCs' don't have clutches

it doesnt have a "clutch" but it does have these friction plates .. i dunno what the real name for it is but in between each metal disc is a ring of friction material to engage the front driveshaft when the electromagnet is energized.

the image below shows two sets from two bw4405 transfer cases

 

[FL Oil Guy]

One key difference in between Dexron II and Dexron III fluids recommended by General Motors is the increased ability of the Dexron III product to function at a lower operating temperature. The same holds true for the Mercron and the Mecron V fluids, which are recommended by Ford.

ATF Fluid can be either single grade or multiviscosity products, They are similar in nature to a hydraulic fluid.

Dexron II & type F SAE viscosity grade 5W-20
Dexron III, Mecron V & ATF Plus 4 SAE viscosity grade 0w-20
Catipillar Powershift SAE grade 10w-30

ATF Friction Characteristics
Different automatic transmissions require lubricants with varying coefficients of friction

Chrysler ATF Plus 4 Moderately slippery
Dexron II, Dexron III, Mercon V Slippery
Ford Type F, TO-4 Grabby

Fluid characteristics also affect transmission longevity. Too little friction results in transmission clutch and band slippage, which causes plate and band deterioration and poor performance. Too much much friction can result in violent shifting which causes an undesirable shift feel, high shock loading and reduced component life.

 

[Derbytown]

So FL Oil Guy, what is your suggestion on the right stuff to put in the TC?
Derbytown
very interesting thread by the way.

 

[Glacier991]

Thank you FL Oil Guy. Your posts are always informative. If there a difference in "slipperiness" between Mercon III and V? I understand the friction modifiers were added for the "shudder" issue (mainly TCC) but wondered why it wasn't reverse compatible. and assumed overall "slipperiness". I know the friction material for the Merc V trannies looks a little different than what i am used to in the merc III trannies. Can you elaborate?