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Can you run trans fluid in xfer case?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by JST12, Mar 14, 2001.

  1. JST12

    JST12 1/2 ton status

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    I think I heard that the NP208 uses transmission fluid in the transfer case. I was wondering if I can do it with an NP205. Does anyone know the properties of the fluids and why not to do it? It would mean less spare fluid to carry. Thx. JT
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    The Np205 is gear drive, the 208 is chain drive. The tranny fluid probably works better with the chain because it is thinner. Run what GM recommends..you already have to use the same fluid in the diffs anyways.

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  3. bigjbear

    bigjbear 1 ton status Staff Member Moderator

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    No you cannot run ATF in an NP205. It takes 80-W90 gear oil. ATF does not have the shear strengh. Meaning it will not provide the lubrication and protection the gears need. The 205 is a heavy duty case. The 208 is a more modern design, not so much weaker, but different. Do not use ATF in the 205, that is probably the only way you can break it.

    Jim '80 GMC
    Freedom First!
    <A target="_blank" HREF=http://www.bigjbear.coloradok5.com>http://www.bigjbear.coloradok5.com</A>
     
  4. Blazer1970

    Blazer1970 1/2 ton status

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    Yes, you can run ATF in a 205. In fact this is what GM recommends behind automatic transmissions in the later model vehicles that use the NP205. It is so common for the trans fluid to leak back into the t-case, that it is better to just run ATF in the 205 than to end up with a mixture of gear oil and ATF.

    Tim

    70 Blazer CST 4X4 350 SM465 NP205
    87 Burb 4X4 350
    01 GMC 2500HD 4X4 Duramax/Allison
     

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