Transfer Case (NP208) Fluid

[SFBullnose]

Hi All,
      I got about 3 gallons for Straight 50 on a deal the other day, and I'm going to do the manual transmission (np435) fluid this weekend.

Can I use this for the np208 transfer case as well ?  All I'm coming up with is that ATF is the way to go, but I'd like to keep it simple if possible.

Thanks for the help !

[Gary Lewis]

I wouldn't.  ATF is the way to go.  Very different lubes.

And, is your "straight 50" gear lube or engine oil.  Two very different things.  I'd not put engine oil in my tranny.

[SFBullnose]

Straight 50 Engine Oil.
Valvoline VR-1 to be exact. I read is cross compatible with the 80w-90 gear oil

Thanks for the help!

[Gary Lewis]

It may have the same viscosity as 80w-90.  But beyond that they are very different.  80w-90 has extreme pressure lubes in it that engine oil doesn't.  And it is not harmful to soft metals, like the synchros in your tranny.

I would NOT use motor oil in a transmission unless the manufacturer recommended it.  And the specs sure don't call for it in the NP435.  The oil that is recommended meets Ford ESP-M2C83-C specification.  You can Google that and you'll find that it isn't motor oil by any stretch.

[SFBullnose]

Thanks for the info!

[IowaTom]

Would the same 80W-90 gear oil be recommended in the transfer case, behind my NP435?  Thanks!

[Gary Lewis]

No.  You can see Ford's recommended lubricants on our page at Documentation/Specifications/Lubricant Specifications, and that shows "Motorcraft Automatic Transmission DEXRON II Fluid" for a transfer case.

[IowaTom]

Duh...I should have remembered to look there first!  Thank you, Gary!

[Gary Lewis]