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Synthetic Fluid Question

GatorFan

By GatorFan
in Ask A GM Technician

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GatorFan Enthusiast

GatorFan

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I have the NON-AUTOTRAC transfer case and had a question about fluids for that and both differentials. I know the rear diff needs 75W90 and my manual says 80W90 (GL-5) for the front diff but a parts guy (dealer) said I can run 75W90 in both the front and rear because I do not have the AUTOTRAC transfer case. Is this correct? :D Do I run DexIII or DexIV in my transfer case? I know the transmission takes DexIII and I want to make sure before I go out and purchase all these fluids in Synthetic. I plan on changing everything to Full Synthetic and want to get the right weights before I crack open any trans pan or differential.

 

Thanks,

icecoldtexan Enthusiast

icecoldtexan

Posted
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You MUST use the Autotrac fluid from GM in the transfer case no substitutions.

 

I used the autotrac fluid from the dealer when I changed my transfer case fluid. The autotrac fluid is blue, but my factory fluid was red, which led me to think the factory filled it with dexron III. The autotrac fluid was only a little over $4 a quart and the transfer case only used two, so to be safe I would always use the autotrac fluid.

icecoldtexan Enthusiast

icecoldtexan

Posted
Posted
I have the NON-AUTOTRAC transfer case and had a question about fluids for that and both differentials. I know the rear diff needs 75W90 and my manual says 80W90 (GL-5) for the front diff but a parts guy (dealer) said I can run 75W90 in both the front and rear because I do not have the AUTOTRAC transfer case. Is this correct? :driving: Do I run DexIII or DexIV in my transfer case? I know the transmission takes DexIII and I want to make sure before I go out and purchase all these fluids in Synthetic. I plan on changing everything to Full Synthetic and want to get the right weights before I crack open any trans pan or differential.

 

Thanks,

 

I replaced the fluid in both my diffs with 75W90 Mobil1 synthetic and haven't had any issues.

GatorFan Enthusiast

GatorFan

Posted
  • Author
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You MUST use the Autotrac fluid from GM in the transfer case no substitutions.

 

You have to use the Autotrac Fluid in you transfer case even if you don't have the autotrac transfer case? My transfer case is the NP261 Manual Shift lever T-case.

 

Thanks

GatorFan Enthusiast

GatorFan

Posted
  • Author
Posted
I have the NON-AUTOTRAC transfer case and had a question about fluids for that and both differentials. I know the rear diff needs 75W90 and my manual says 80W90 (GL-5) for the front diff but a parts guy (dealer) said I can run 75W90 in both the front and rear because I do not have the AUTOTRAC transfer case. Is this correct? :driving: Do I run DexIII or DexIV in my transfer case? I know the transmission takes DexIII and I want to make sure before I go out and purchase all these fluids in Synthetic. I plan on changing everything to Full Synthetic and want to get the right weights before I crack open any trans pan or differential.

 

Thanks,

 

I replaced the fluid in both my diffs with 75W90 Mobil1 synthetic and haven't had any issues.

 

 

That's the fluid I bought last night for both diffs. I used the same stuff in my wife's 4X4 4Runner and have had zero issues with it.

 

Thanks again for the info.

GatorFan Enthusiast

GatorFan

Posted
  • Author
Posted
Early models used a different Autotrac fluid and later changed to the blue. This only applies to Autotrac.

 

Thanks for the assistance and info redvette.

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