Hi i've been reading endless pages on this and i see Royal Purple, Syn Go and GL-5 synthetic as recommendations. Will any work or have we found through trial/error one to be best? Do you also recommend adding an additive? if so which type? thanks for the help.

 

Save your money...Dextron 6 works great and is a few dollars cheaper

 

The Dextron 6 can be used on the rear diff right?

 

I'm not too sure about the rear.....

 

The rear differential and the transfer case both use the same fluid (75W-140 full synthetic based fluid). That is where the GL-5 comes in to play as GL-5 is a standard for that type of fluid, no so much a brand name. People have used Redline, Royal Purple, etc and have not had any issues that could be related to the fluid. I personally use Mobil 1. 6 of one, half a dozen of another. As long as it has the GL-5 rating, you will be just fine.

Now, as for the Dexron VI fluid, I personally would not recommend putting that in the transfer case. Dexron VI fluid is a transmission fluid, not a gear fluid. The physical properties of the two are completely different. I have a feeling that if you put the Dexron VI fluid into the transfer case, you will have serious issues in a short period of time. Now, if you plan on putting it into the transmission only, then you should be fine. But, again, I would double check the specs on the fluid and see how that compares to what is recommended. As long as it has the same ratings maintained (or exceeded), you will be just fine.

 

Good to hear, thanks for the explanation