I have a 72 F250 with a Dana 60 in the rear. Open diff.
Took the cover off and drained out the old oil. Looked in my service manual and owner's manual but could not find the "weight" of the oil to put back in the differential.
What weight of gear oil does a rear Dana 60 take?


75W-90
75W-140
80W-90
85W-140
SAE 90
...

 

All of them. It originally was specced as 90w, but there are many options today. It depends on where you live and how you drive. In a hot place with no winter weather, you want a thicker oil, say a viscosity over 90. If a cold place then want a lighter oil below 90. If a lot of heavy and hot towing, then a heavier oil. It is just like motor oil. Hotter, go heavier. Colder, go lighter. And W means for winter use.

 

Thanks for the reply.
I'll probably use 75W-90 gear oil.

 

A 75w140 synthetic should help with mileage a little. It might not be much, but I know switching the big trucks to synthetic picked up about a 10% gain.

 

I got a good deal on some synthetic for a cheap, cheap a few yrs ago.
So, I put it in the *** end, and had big trouble with it working pass the drum seals soaked up the brake lining on both wheel. So replaced the oil after drained that crap out. Now 8000 mile later it did the same thing with the 90wt in it. Axle sealing area not any wear grooves. This time, I flushed out the whole ring & pinion with a cleaner then did the inner axle tubes. So cleaned 99.99% of that synthetic that may have mixed in with the old 90wt that's been coated with in the housing. Also the transfer case seals had all started leaking. Drained it out and leaks stopped. Did not add any to nv4500 tranny cause that's what it takes is 75 wt synthetic.
So for me, I will never put in any synthetic where it's not called for.. my 2 cents ....orich