I am currently using Royal Purple 85W140 gear oil and I will have to say it works extremely well. Very smooth shifts, no gearbox noise, and at idle its just quiet. I know mazda recomends either 75W90 or 80W90, but to me that is just a good universal weather condition oil. This stuff I have in it now just feels so much better. I dont live in a really cold climate so I went with the thick stuff. I was shocked after I changed to it, as soon as I drove off I could notice a very large difference in the up and down shift, all around it improved the drive. Quiet and smooth.

 

That factory trans fluid was like water, wasn't it?

CRH

 

You have to remember scout...Mazda is just putting in the absolute bare minimum required to keep the engine and tranny "safe"...85W140 is perfect,...Charles you're right..when i pumped my tranny i thought i somehow had gotten water or something mixed in with the fluid...i don't know how the hell it was even lubing anything...