Hi all. Question about gear oil. I'm going to be dropping my transmission on my 79 brat, which is a single range. What is the recommended gear oil for the transmission and rear dif? I put some 75/90 in the transmission to top it off after it had been leaking but I have not done a full drain/fill on it, and I suspect both the trans and rear differential could use it. However, I can't find any factory recommendations as to what specifically goes in each. Any help? Thanks in advance.

Extra S. Its what comes in Subarus right outa the factory. on top of that its amazing to use. Subaru dealerships dont use it on vehicles they service because they have contracts with another company Valvoline or amz? cant remember. 

Thanks for the response.

 

So,

 

http://www.amazon.com/Subaru-75W90-Extra-S-Transmission-Fluid/dp/B007L6Q1EK

 

This one ^^^ ?

 

For both Trans and rear dif, yes? And do you know the capacities, by chance?

That's it!

Not sure on the cap though. Rear will prolly be near 1 quart. And I know the eJ 5speeds hold just under a gallon. 3.7quarts if I remember correctly. But not sure about the brat stuff

So I wonder if this was indeed used/recommended by the Subaru factory in 1979?

This is how we buy it at our shop. Comes right from Subaru in Japan, made by fuji heavy industries. I could almost guarantee that it did. 

Edited May 30, 201411 yr by Prwa101

Most stealerships do not use the good stuff with regular service, but most do have it in the shop if you request it. And some dealerships will even pump it out by the quart for you, I keep a small gas can for extra S only. If any transmission comes in making noises or hard to shift, you can bet that they will try a change with extra S before diagnosing anything.

Edited May 31, 201411 yr by Ibreakstuff

Thanks for the input guys.