My manual shows different oils and levels for different axles. My 350 has a C9 rear end and I am trying to figure out if it is a Dana or Conventional. Anyone got any information on what the difference might be? How about the front? 1997 F350 PSD. I have 80w-90, is this okay?

Thanks,

Aaron

 

The 80W-90 should be fine. If you do a lot of towing or hauling heavy you might consider going with a 140wt gear oil.

If you have synthetic in the differentials, I would not mix them with standard gear oil. As for oil levels, I fill them up to the fill plug. When oil starts running out, it's full.

 

You should have a 10.25 rear and a dana 60 front.

 

Your front axle is a Dana 60, your rear is a Sterling 10.25 with 3.55 limited slip. Ford recommends 75w-140 gear oil, make sure you use oil that has the friction modifier for your limited slip, or buy some to add.

As said above, it's full when it starts to run out of the fill plug.

 

Thanks Everyone. I checked them and found the rear to be slighty low and the front was fine. I topped it off with what I had on hand. The fluid appeared to be red like tranny fluid, but definitely smelled like gear oil. Wonder what the PO used...Aaron