Transmission and differential oil


Hopefully my cougar is soon going to be able to move under its own power.
Before i get too excited i would like to do a fluid change as they are probably 25 years old.

What do you guys use for the 3spd manual gearbox ?
I’ve read online people recommending Redline MT90 or SAE80W90 GL-4
Will that work, and should i use the same for the differential ?


You should not use a synthetic oil in either of them. Synthetic oil does not “climb” as well as conventional oil. Many transmission rebuilders (David Kee for example) will not warranty any of their boxes if used with synthetic oil products.

Personally I like to use Ford lubricants in both differentials and standard transmissions.

Somehow I assumed the lubricants listed with ford number in the manual weren’t available anymore. Where do you get these ? from ford dealerships ?

Right. Any Ford dealer should have factory - or factory approved - lubricant in stock.