gear oil

[droppinbottom]

i just replaced my rearend to a 4bolt and am about to add new gear oil to the rear axle gear box and i was wondering if the oil i have is too thick or not for it.
i have a quart of the royal purple gear oil and it says it is 85w140.

 

[kidwiththelaser]

Try to get some GL5 75w90 in there. Synthetic if you like, but its just a rear differential theres not much too it.

 

[droppinbottom]

yeah the royal purple is synthetic and meets gl4/gl5 but i just didnt know if it would be too thick. guess ill just give it a try

 

[jongreene]

i have mobil 1 in mine, no complaints probably just as good and i think cheaper, like kidwiththelaser said...not much to it.