09 5 speed gear box oil

[Truckedup]

Time to change the tranny oil, 09 5 speed 4.0 4x4, 95,000 miles...Do you guys recommend something other than what Ford says? With the AX15 5 speed in my Jeep and the NV3500 5 speed in my Silverado , Redline oils of the proper grade seemed to make them shift better especially when cold..
And what's the actual oil capacity? thanks

 

[RonD]

Mercon V ATF is spec for the M5OD-R1 manual transmission, 1988 to 2012 Rangers, yes Automatic Transmission Fluid in a manual trans
Transfer case as well, but Ford does make a different version now specific to BW1354 transfer cases

Synthetic versions can go either way, lol, some say better, some say not and switch back, so anecdotal science at best

 

[4x4junkie]

Spec for pre-2008 M5OD transmissions is actually Mercon (not Mercon V)

Ford (now) says Mercon V is compatible with Mercon applications (used to be they said using it would void warranties... lol), however I've still seen far too many cases of shifting problems that occur in manual transmissions after using it, making clear the reason why Mercon fluid is still available as "Dex/Merc" fluid.
Mercon V however is spec for 2008-2011 M5OD, so it "should" be safe to use in a '09.

As for synthetics, I put Synchromax (Royal Purple) fluid in my '90. I think I noticed a very slight better ability to maintain speed in 5th going up grades, but beyond that I didn't really notice a whole lot else. Shift quality did improve some, but once in a while (maybe 1-2% of the time) it still balks going into 1st gear and I have to slip the lever back toward 2nd, then come back to 1st before it goes in (I suspect it was subjected to Merc V at some point, it was a used trans from another '90 w/123K I bought around '09).

 

[KingSlew]

Is there any way to tell if Merc V has been used???

 

[4x4junkie]

Is there any way to tell if Merc V has been used???

I s'pose maybe some forensics-like test exists that could test for traces of additives unique to Mercon V, but I doubt there's any good way for an average schmoe like us to be able to tell for sure.

Best I can do is describe symptoms I've observed...
One appears to masquerade as a clutch that doesn't fully disengage (like as if a leaky slave, warped disc, etc.), however if you hold light pressure on the stick, it'll drop right into gear after about 3-5 seconds (or if it doesn't, shift into 2nd and then come back to 1st and it'll easily slip right in).
Notchy or 'chunky' shifts is another I've noticed on mine as well as a friends '93 that I know had Merc V put in it (his problems began right about a week or so after a visit to a Jiffy Lube in '08).
My best guess is that an additive used in Merc V is too slippery for the synchros to function properly.
The unfortunate thing is, once it sees Merc V, the damage seems to be permanent. Going back to Mercon (Dex/Merc) fluid improves things somewhat, but it never seems to fully recover to what it was beforehand (my friend's truck had Merc V for maybe a half-year, but 3 oil changes and 40,000 miles later using Dex/Merc it still behaves a lot like my BII's M5OD, which I've also put about 40K on mine as well). A rebuild w/new synchros would probably fix it (Merc V should not damage any hard parts such as gears or bearings).

My '94 OTOH still shifts as if new (has 116K or so thereabouts on it). I am not about to try putting Merc V in it just as an experiment lol.