Transfer case fluid 97 4.0 OHV 5R55E

[Daymon Powell]

What is best tx. Case fluid currently using dex/ mercon. Considering. Valvoline SYN. TCF any input much appreciated.

 

[410Fortune]

mercon III is the best fluid for your t case
Do NOT use mercon V
I do not run full synthetic atf in these cases, just Mercon III and change it yearly or bi yearly

 

[christopherjost]

Best bet is Mercon LV. As Fourten mentioned, do NOT use Mercon V in transfer cases.

 

[96eb96]

What is best tx. Case fluid currently using dex/ mercon. Considering. Valvoline SYN. TCF any input much appreciated.

Like others said...
Either:

1. Plain Mercon (not V!!!). This is something you would buy in Walmart, it would say Merc/Dex compatible fluid. Least Expensive.
2. Mercon LV (Superceded by Ford from the original Mercon Recommendation. Currently Recommended by Ford for our transfer cases). Ford does not license plain Mercon anymore.
3. Valvoline Transfer Case Fluid (which is probably their Synthetic Trans fluid in a different bottle).

 

[Desert_AIP]

I was just researching this.
I understand the Ford replacement for Mercon is XL-12 (bottle marked as "Transfer Case Fluid").
I'm having trouble finding actual Motorcraft XL-12/Transfer Case Fluid.
The Valvoline synthetic TCF states it's XL-12 compatible.

 

[96eb96]

I was just researching this.
I understand the Ford replacement for Mercon is XL-12 (bottle marked as "Transfer Case Fluid").
I'm having trouble finding actual Motorcraft XL-12/Transfer Case Fluid.
The Valvoline synthetic TCF states it's XL-12 compatible.

XL-12 is not sold by Ford anymore. There may be a few bottles of NOS somewhere. If the dealer puts XL-12 in their system Mercon LV comes up. Could be LV was enhanced for transfer case use. The VV product is compatible with XL-12, as much as a $3 bottle of regular Mercon is compatible with the original spec.

 

[Desert_AIP]

XL-12 is not sold by Ford anymore. There may be a few bottles of NOS somewhere. If the dealer puts XL-12 in their system Mercon LV comes up. Could be LV was enhanced for transfer case use.

Thanks for the clarification. No wonder I couldn't find the XL-12

 

[Daymon Powell]

Like others said...
Either:

1. Plain Mercon (not V!!!). This is something you would buy in Walmart, it would say Merc/Dex compatible fluid. Least Expensive.
2. Mercon LV (Superceded by Ford from the original Mercon Recommendation. Currently Recommended by Ford for our transfer cases). Ford does not license plain Mercon anymore.
3. Valvoline Transfer Case Fluid (which is probably their Synthetic Trans fluid in a different bottle).

Like others said...
Either:

1. Plain Mercon (not V!!!). This is something you would buy in Walmart, it would say Merc/Dex compatible fluid. Least Expensive.
2. Mercon LV (Superceded by Ford from the original Mercon Recommendation. Currently Recommended by Ford for our transfer cases). Ford does not license plain Mercon anymore.
3. Valvoline Transfer Case Fluid (which is probably their Synthetic Trans fluid in a different bottle).

 

[Daymon Powell]

Like others said...
Either:

1. Plain Mercon (not V!!!). This is something you would buy in Walmart, it would say Merc/Dex compatible fluid. Least Expensive.
2. Mercon LV (Superceded by Ford from the original Mercon Recommendation. Currently Recommended by Ford for our transfer cases). Ford does not license plain Mercon anymore.
3. Valvoline Transfer Case Fluid (which is probably their Synthetic Trans fluid in a different bottle).

I knew not to put Merc.V in tx.case,but new info. on Merc.LV. Wally doesn't sell reg.dex III in qts. anymore so last time I used the high mi.,no problems .This time I will use the Merc.LV
Thanks for all the info. DMP

 

[96eb96]

I knew not to put Merc.V in tx.case,but new info. on Merc.LV. Wally doesn't sell reg.dex III in qts. anymore so last time I used the high mi.,no problems .This time I will use the Merc.LV
Thanks for all the info. DMP

This looks like good stuff. Specifically for Dex/Merc:

Robot or human?

Advance auto has LV for $7.99. Either would probably be fine.

 

[Falcon_LS]

Since it calls for regular Mercon/Dexron III, I've been running a TES-295 approved fluid.

 

[96eb96]

Last couple of years for original 1354 TransferCase on this 2001 Ford ExST V6~4.0L~SOHC, been using
Valvoline Dex\Merc\MerconLV~FullSyn ATF (1qt or 5qt bottle) from WalMart.

Robot or human?

Couple of quarts left in a 5qt bottle on garage shelf now, sharpy marked "For 2001 ExST TransferCase ONLY".
TC seems happy running+shifting 2WHi~4WHi~4WLo without leaks or operating issue.
Did have to replace 4x4 control module & shift motor a couple of years ago, but original TC itself still running good.

To be clear,
use "Dex\Merc\Mercon\MerconLV" compatible ATF in the 1354 TransferCase,
and "MerconV" compatible ATF in the 5r55e Transmission,
do NOT mix these up.
Hope this helps.
D
View attachment 322364

That is likely what goes in their Transfer Case Fluid bottle, for a few bucks more.

TC is usually neglected. The clutch creates plenty of heat, and on trucks without 2wd mode(e.g. non 95-96) it is always on. I'm sure the chain does too. I know also some of these cases fail because the case ovals out, I don't know if fluid can play a role in that but according to one trans builder, he believes so.

Probably should have a 30-60K OCI. If used in Low often, or towing probably closer to 30k. It is real easy to change on these trucks too. Under $20, maybe even under $10 if you can find a basic dex/merc.

 

[Desert_AIP]

Sidebar question:
Since Power Steering is also specced for Mercon, I assume the replacement is the Mercon LV.

ETA: Found this other thread with a service bulletin referenced.
So looks like I can use Mercon V in both the transmission and power steering, but still need LV in the transfer case

Power Steering Fluid

SB 07-1-7

01/22/07
MERCON(R) ATF REPLACED BY MERCON(R) V AS A
SERVICE FLUID FOR SOME POWER STEERING
SYSTEMS

FORD:
1996-2007 E-Series, Explorer, Ranger

 

[96eb96]

Sidebar question:
Since Power Steering is also specced for Mercon, I assume the replacement is the Mercon LV.

ETA: Found this other thread with a service bulletin referenced.
So looks like I can use Mercon V in both the transmission and power steering, but still need LV in the transfer case

Power Steering Fluid

SB 07-1-7

01/22/07
MERCON(R) ATF REPLACED BY MERCON(R) V AS A
SERVICE FLUID FOR SOME POWER STEERING
SYSTEMS

FORD:
1996-2007 E-Series, Explorer, Ranger

PS system does not have any clutches so mercon V is the right fluid.

 

[SparkyF250]

Don't use Mercon V use either Ford XL-12 or Valvoline Transfer Case fluid is what I use in all my vehicles. 91 F350, 93 F150, 00 F350, 05 Explorer and an 05 F250. Dex/Merc and LV will work too I just use stuff designed for T-cases personally.
Valvoline Multi-Vehicle (TCF) Conventional Transfer Case Fluid 1 QT
Genuine Ford Fluid XL-12 Transfer Case Fluid

 

[96eb96]

Don't use Mercon V use either Ford XL-12 or Valvoline Transfer Case fluid is what I use in all my vehicles. 91 F350, 93 F150, 00 F350, 05 Explorer and an 05 F250. Dex/Merc and LV will work too I just use stuff designed for T-cases personally.
Valvoline Multi-Vehicle (TCF) Conventional Transfer Case Fluid 1 QT
Genuine Ford Fluid XL-12 Transfer Case Fluid

Too bad it is discontinued by Ford. It is superseded with Mercon LV. If anyone went to the dealer and got a TC service, they would do a fill with Mercon LV.

 

[EB4X]

410 who I respect stated: "I do not run full synthetic atf in these cases, just Mercon III and change it yearly or bi yearly"

...yet all they had at Autozone was the full synthetic Transmax Mercon LV .... I'm assuming I'll be okay using this....anyone want to chime in on why NOT to use this ? ( full synthetic) on our T cases ...??

 

[donalds]

why NOT to use this ? ( full synthetic) on our T cases ...??

Its not good for the friction/wear parts in the t case

 

[EB4X]

Thanks Donald.... going to return and find standard...

 

[CDW6212R]

Old subject. Mercon I is the correct fluid, always was and always will be.

That is Mercon I, .... not Mercon III(there never has been a Mercon III, the old fluid was Mercon I and Dexron III, labeled Mercon/Dexron III on the bottles). That is simple math, the I is implied, Mercon is Mercon I, and again, not Mercon III.

All of the newer TC fluids seem to be the equivalent of Mercon, they simply cost a whole lot more. The XL-12 was $20-$25 a quart early on, people gobbled that up. Dexron III is perfectly adequate for the TC's. Valvoline is an old favorite brand of mine, I bought two cases of their TC fluid for $30 each from Amazon when it first came out. So $6 per quart is a decent price for the TC fluid, Dexron III is still available and runs about $5, the other fluids are too expensive given the options mentioned here.