Ok, I don't have a Dana book, so I'm asking on here.

I have an 79 F350 4x4 with Dana 60 front and back. It has 3.54 gears on both.

Rear:

3.54 D8TA TB
603901-1

Front:

630093B on left side of the housing

3.54 D8TA YD
610023-2

Does those tell anything other than the axles being 60's and 3.54 gears, like if it has limited slip?

I am going to change the gear oil on both axles. What gear oil should I use? 80W-90? Or 80W-140?

Thanks!

 

[updated:LAST EDITED ON 16-Mar-02 AT 10:17 AM (EST)]Either oil will work just fine. The 80W90 means at 0 degrees the oil will have a vescosity of 80 and at 200 degrees the oil will have a vescisity of 90. A lower viscosity flows thinner the higher viscosity means it actually thinkens when it gets hotter due to additives they add in oil. When you buy a oil with the W in the middle the W actually means winter the # before the W is the viscosity in winter temperatures and the # after the W means the viscosity at summer temperatures which the API uses 200 degrees for an average temp when testing viscosity. But as for the W in a grade of oil all the W means is winter call the API if you don't believe me.


So the 80W140 means if you run in a hotter climate or pull a trailer alot the 80W140 would be a better oil since the viscosity raises to 140 at 200 degrees

Now for your question of limited slip or locker The rear might be a limited slip it depends what the customer who bought the truck originally optioned for as for the front it is a open differential