Mercon vs. Mercon V??

[Jason_J]

Somewhere there is a FSB that says Merc V should be used instead of Dex/Merc. My manual calls for Mercon in the Manual trans, transfer case and power steering pump. Is it safe to assume that Dex/Merc is fine as long as it's not mixed with Merc V?

Thanks,
J

 

[Earl43P]

MerconV is synthetic.

It's better in every possible way, for each component you listed.

I use it to quiet noisy Ford Power steering pumps. Almost miraculous, the difference it makes.

I also put it in my old 2000 4wd trans/tcase/ps pump.

I put synthetic gear oil in the differentials (you have to suck it out of the front axle).

Synthetic lubes are simply better, hands down.

 

[exbass94]

Mercon V is not necessarily synthetic, in fact most of the time it's merely a synthetic blend. You can mix the two just fine, nothing bad will happen. You can continue using regular Mercon or use Mercon V, it doesn't really matter.

 

[Earl43P]

^^I'm glad you posted that; I assumed that MerconV specified synthetic base.

I stand corrected. It can any of the GroupII or GroupII plus oils.

Ford has specified MerconV for at least the last 8 years of production.
Most of the aftermarket MerconV you find on the shelf will be at least partial synthetic.

Some good reading here: http://www.ford-trucks.com/forums/114482-base-oil-technology-group-i-iv-what-it-all-means.html?fb_xd_fragment#?=&cb=f358bfa6271581e&relation=parent&transport=fragment&frame=f23fabaa6b878f

 

[Jason_J]

Cool, thanks guys!!

 

[4x4junkie]

I wouldn't be so fast to assume Mercon V is always better.

There have been several reports of Mercon V causing poor shifting in earlier M5ODs. I suspect it may be too slippery for the M5OD's synchros to function properly.

Personally I would stick with plain Mercon (Dex/Merc nowadays) in the M5OD, and use the Mercon V everywhere else (T-case, power steering).

 

[Earl43P]

I too recall that, something about phenolic/plastic synchros vs. bronze?

I put the Pennzoil synthetic ATF / MerconV in my 2000's MO5D and it felt fine.

More discussion here: http://www.therangerstation.com/forums/showthread.php?t=101540

and here:
http://www.therangerstation.com/forums/showthread.php?t=92472