Manual trans and transfer case ATF

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Bronco1

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I've just picked up a '96 Bronco 5.0 w/ 5 spd manual trans. It's got 258k miles and there's no service records. I'm getting ready to do a major service and found an Owner's manual that indicates that the trans (M5OD-RD2) and transfer case (BW 1356) use Mercon. I haven't serviced something like this in 40+ years so, I was a bit surprised it wasn't gear oil. Does anyone have any experience with Mercon vs the new synthetics that are Mercon approved in such applications?

Thanks in advance!
 
Originally Posted By: simple_gifts
You haven't really indicated your intention, but Wally World has Dex/Merc ATF cheap by the gallon.


by saying "major service" I meant I plan to change out all the lubricants (i.e. engine oil, trans and transfer case, front and rear differentials)
 
I would think most of the Ford Mercon transmission vehicles of the 1990's were upgraded to Mercon V in 2002.

Fwiw my 1999 FWD Lincoln (transfer case) was specced for Mercon. By 2002 the exact same trans specced Mercon V. So you really could use either Mercon or Mercon V today. SuperTech has a Mercon V at $4.75/at, as do Castrol, Amalie, and others. Mercon V's are at least semi-synthetic and probably a better overall fluid than Mercon. And the SuperTech and Castrol have Ford approvals as well. That's would I would use instead of Mercon where probably no one carries a spec identical to Ford's original one.
 
My OBS seen mercon in trans, type f in P/S. 15years into the back spec, I am plunging into the mercon V.

You could use either, or. But IMHO I would choose the mercon V, semi-blend+, thinner, ect.
Don't forget the turkey baster P/S flush.


Harvey
 
Originally Posted By: bioburner
I bet if you read the bottle of Valvoline Maxlife it probably will have you covered


Yes, they say you're covered. But, it doesn't change the fact that MaxLife is an LV ATF with a viscosity of 5.9-6.0....and the Mercs/Dex were specced starting off at 6.8-7.5 with nearly all of them at above 7.0. Never could see how MaxLife covers regular MV ATF and LV ATF's. I know people use it as one size fits all. It's true the Mercs will shear down into the 5's with enough miles. But, until then, your viscosity is on the low end with MaxLife. I'd rather use a Ford approved Mercon V fluid, especially since they are fairly inexpensive. The add pack on the MaxLife is quite stout....I love that. I just wish it had a higher viscosity as well. It's really a Dex VI.
 
The pan on my '97 Mercury Tracer 5 speed recently had to be replaced due to a tiny rust pinhole.

I refilled it with MaxLife.
 
Originally Posted By: 69GTX
I would think most of the Ford Mercon transmission vehicles of the 1990's were upgraded to Mercon V in 2002.

Fwiw my 1999 FWD Lincoln (transfer case) was specced for Mercon. By 2002 the exact same trans specced Mercon V. So you really could use either Mercon or Mercon V today. SuperTech has a Mercon V at $4.75/at, as do Castrol, Amalie, and others. Mercon V's are at least semi-synthetic and probably a better overall fluid than Mercon. And the SuperTech and Castrol have Ford approvals as well. That's would I would use instead of Mercon where probably no one carries a spec identical to Ford's original one.
I don't think you're suppose to use Mercon V in transfer cases.
 
I've had two trucks with that exact same transmission and transfer case combo. (93 and 95 F-150s) I just used Super Tech Dex/Merc in them.
 
Originally Posted By: Bronco1
I've just picked up a '96 Bronco 5.0 w/ 5 spd manual trans. It's got 258k miles and there's no service records. I'm getting ready to do a major service and found an Owner's manual that indicates that the trans (M5OD-RD2) and transfer case (BW 1356) use Mercon. I haven't serviced something like this in 40+ years so, I was a bit surprised it wasn't gear oil. Does anyone have any experience with Mercon vs the new synthetics that are Mercon approved in such applications?

Thanks in advance!


I have the M5OD in a Ford van, and run it on Mobil 1 ATF. It's pushing 30 years old now, and the transmission is still shifting and working fine. The transfer cases in my Liberty and Rubicon both spec ATF+4, and have so for years. I have no problems and haven't heard of any associated with using ATF vs. gear oil in them.
 
Redline MTL in the tranny. Ford Transfer case lubricant for the transfer case. Or ANY Atf will do, I use Mobil 1 and chanage very 100KM
 
Originally Posted By: Bronco1
Originally Posted By: simple_gifts
You haven't really indicated your intention, but Wally World has Dex/Merc ATF cheap by the gallon.


by saying "major service" I meant I plan to change out all the lubricants (i.e. engine oil, trans and transfer case, front and rear differentials)


Ok; I guess I was not sure if you were looking for Mercon or were intent on using Mercon LV.

Bluesteam indicates using MTL in this transmission; I would (and have) used Redline D4 in my B2300 (ranger) which also specs Mercon. It is a thinner lube.
 
Originally Posted By: Bronco1
Originally Posted By: hatt
I don't think you're suppose to use Mercon V in transfer cases.


You are correct. I just found this: https://www.fcsdchemicalsandlubricants.c...mission%20Fluid

Ford indicates not to use Mercon V or LV Mercon for transfer cases. I haven't found anything one way or the other regarding Mercon V for the manual trans.

---------------------

If that's the case, then it's a similar situation that GM had with their DEX III ATF being used in Tremec manual transmissions. When they let the Dex III licenses lapse they eventually concluded not to use Dex VI or LV ATF's in those transmissions....stick to the DexIII. I would image any stout Dex III ATF that is specced in transmissions would work in a transfer case (ie M1 ATF, Red Line ATF, Amsoil ATD ATF, Honda ATF, etc.). Ford specs MerconV in the transaxle/transmission of my 4.6L DOHC. The operating viscosity of the Mercon and Mercon V (and DexIII's) are usually above 7.0 cSt.
 
I have a 2002 F-150 with the same tranny. It calls for Mercon as well as in the transfer case and power steering. I had a 1989 F-150 with the same tranny and it ran great with the Mercon. My 2002 F-150 shifted horribly with Mercon. I used Royal Purple MT and the shifting was sooo much better. Most likely most spec'd manual transmission fluids will improve the shifting quality. In both vehicles I've used Mercon in the transfer case as well as in the power steering.

Whimsey
 
Others have suggested the universal ATF from Walmart in the gallon bottle (priced around $12) its an OK fluid. My truck is a GM and their spec was Dex III but has a TSB to use a heaver oil such as 10w30 syncromesh because its more slippery... After looking at other fluids, I went with ATF+4 because it has a high viscosity and a synthetic... The transfer case it not too picky about the fluid if its changed on a regular schedule... My suggestion is to add LubeGard to the specified fluid, its good stuff and fairly inexpensive.
 
Originally Posted By: Dufus2
Others have suggested the universal ATF from Walmart in the gallon bottle (priced around $12) its an OK fluid. My truck is a GM and their spec was Dex III but has a TSB to use a heaver oil such as 10w30 syncromesh because its more slippery... After looking at other fluids, I went with ATF+4 because it has a high viscosity and a synthetic... The transfer case it not too picky about the fluid if its changed on a regular schedule... My suggestion is to add LubeGard to the specified fluid, its good stuff and fairly inexpensive.


What's the number of the TSB, year of the truck, and are you referring to the TSB in terms of the Manual Transmission or the Transfer Case? I doubt it's the TC. As long as I can remember, the electronic TC's have used ATF or the "XTrack" series of fluids.

The GM synchromeshes have special friction modifiers for Manual Transmissions, which modify the friction coefficients.

LubeGard does nothing for a TC.
 
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Ford TSB #06-26-1 for manual transmissions. It shows all M5OD's now getting Mercon V. I won't use it. My '04 Ranger with M5OD-R1 shifted fine on Valvoline Mercon/Dex III ATF. I put Valvoline Mercon V at 100K. Stiff and notchy shifting. I dumped it at 105K and refilled with Valvoline Mercon. Shifting back to normal, although the M5OD was never smooth like the 4-speed in my '74 MG-B.

IMO, I think the Mercon V is 'too slippery' for the M5OD.
 
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