Help on Transfer Case Fluid

[m2pc]

Was wondering if I could get help, recommendations and get educated on the replacement for the oil in a transfer case.

The manual for this vehicle, it states:

"Use a SAE 90 or SAE 80W-90 viscosity gear oil, API classified GL4 or GL5 only
Viscosity SAE90-above 0 degrees F (-18C)
SAE 80W-90W-below 0 degreesF (-18C)"

I live in the New England area, and it does get cold, but I don't believe below 0 degrees F very often. It doesn't seem to matter whether GL-4 or GL-5 is selected, as they spec both out, but given a choice where both are acceptable, which one to choose, my guess would be the GL-5.

Second, since I am considering a synthetic, I believe Amsoil makes an 80w-90, and for both the GL4 and GL5 spec, I would not think that the higher temperature would as critical in selecting between the 80w-90 and 90. Besides, any recommendations on an SAE 90 if that is better for my application?

 

[7TFord]

My Toyota 4x4 calls for the change to an 80W for the summer months also but I have been running a Castrol synthetic 75/90 all year around since new with no problems. Unless you are heavily loading your differential and case in the heat you won't likely need the extra protection and the lighter weight in the cooler temps will flow quicker. My spec only allows me the GL-5 option and I am not sure of the differences between the two requirements.

[ January 01, 2004, 02:56 PM: Message edited by: 7TFord ]

 

[MolaKule]

m2pc,

Here are my pics from the site supporters that help keep this site running so we can answer questions like yours:

http://www.amsoil.com/products/tgr.html

http://store.avlube.com/mob1syngearo1.html

http://www.schaefferoil.com/data/740-741.htm
http://www.schaefferoil.com/data/267.html

http://www.myoilshop.com/AutoPrds.html

 

[m2pc]

Thanks guys!

I think I will go with the GL-5 and SAE 80w-90.

I have already purchased from a site supporter and will prefer to continue to support those that support this site. The info here is great, drawback is there is SOOOO much to read up on.