Differential oil

[moparmucelli]

hi guys just wondering what's a good differential oil to use in my 8 1/4 rearend 3.21 gear ratio non posi?

 

[73Swinger18]

 

[RustyRatRod]

80w90 is just fine.

 

[moparmucelli]

Ok great thanks

 

[Mash340]

80 90 what? Full synthetics semi synthetics straight conventional oil??

 

[71DodgeDemon340]

75w90 lucas full synthetic.

 

[RustyRatRod]

75w90 lucas full synthetic.

Why? That's not the spec it calls for.

 

[71DodgeDemon340]

Why not? Lucas makes a great product.

Sure the 80w-90 will work but 75w-90 seems easier to find and has a better winter rating while having the same benefits of the summer rating. Plus once you put full syn you will never have to change it again