Royal purple gear oil (max gear)

[01TrueBlueCobra]

I have a solid axle w/4.30 gears and want to know what wieight RP gear oil to use 75W90 or 75W140

 

[BuffaloZone]

I have a solid axle w/4.30 gears and want to know what wieight RP gear oil to use 75W90 or 75W140

I'm using Royal Purple 85W140.

 

[Kilgore Trout]

What does the little tag say on the diff cover? Uh-huh... 75W-140

 

[Cobra Jay]

What does the little tag say on the diff cover? Uh-huh... 75W-140

75-90 or heavier than 75-140 won't hurt anything reguardless what the diff tag says.