My manual calls for 75-140 synthetic (I tow a 10K 5vr). Whats the difference between these two types of fluid? I can find the 85-140 without any problems locally - the 75-140 is tougher (like I cant find any at the major auto parts stores in OKC).

 

Mobil 1 makes the 75W140. Auto Zone carries it here in SW Missouri. I would not go with a 85W140. Only pulling 10K you would be OK with Mobil 1 75W90.

 

Amsoil makes a 75-140

 

[quote author=AFSMSgt link=board=4;threadid=10761;start=0#102652 date=1044831964]<br>My manual calls for 75-140 synthetic (I tow a 10K 5vr). Whats the difference between these two types of fluid? I can find the 85-140 without any problems locally - the 75-140 is tougher (like I cant find any at the major auto parts stores in OKC).<br>[/quote]<br>The Napa store in Yukon handles Royal Purple which comes in a 75w-140

 

I've tried NAPA (Yukon, MW City, OKC) - they only carry 85-140. If I order AMSOIL, looks like I'm paying 12 bucks a qt. Royal Purple is a bit better, but I can't find any reputable sites that sell it. Any advice on online stores is appreciated... ???

BTW: Geno's Website shows the capacity to be 6.8 pts...is this correct?

 

http://www.oiltownusa.com is where I buy my Royal Purple! Pretty good prices! ;D<br><br>Tony

 

I assume you have the Dana 80 axle, it's capacity is 5.05 quarts and is considered full by DC when the fluid level is 3/4&quot; below the filler plug.<br><br>I've used both royal purple and amsoil in the past with good results. I have a preffered customer account with amsoil, my cost for 75W-140 would be $9.35 per quart plus shipping and sales tax.