Compatible with other automotive gear oils????

[whitearrow]

Ok fellas. I got a question about gear oils. A little back story. I changed the rear diff oil in my wife's 2016 Toyota 4Runner which calls for a GL-5 spec. So I wanted to try a synthetic gear oil and it spec'd for 2.8 quarts. So, I buy 3 quarts of valvoline synpower 75w-90 and at the end of pumping in almost 3 quarts still no gear oil dribbling out of fill hole. So, thankfully I had some rotella 80w-90 conventional gear oil in the stash that was also GL-5 spec'd and it held another quart of of the rotella conventional and part of another. So, to my question and to the title of my thread. Both the valvoline synpower and the Rotella conventional say "compatible with other automotive gear oils". Am I safe with my current situation in my wife's 4Runner rear diff oil with the valvoline syn and rotella conventional mixed?
Thanks,
Big Ed

 

[MolaKule]

You're ok Big Ed as most GL-5 gear oils contain similar additive packages, and the viscosities of the gear oils you used are very similar.

 

[Rand]

it will be fine. You might consider it a flush out and change it early.. after 5000 or 10000miles if it bothers you.

Seems odd to take that much as the manual says 2.9qt.

You filled it up with the vehicle level right?

 

[whitearrow]

Absolutely. That was my thought too. I even went and got the level and laid it on the driveway where I was changing fluid. Bubble was perfectly level.
Thanks,
Big Ed

 

[Hall]

You likely never get all of the 'old' fluid out so there's always some mixing. Won't be a concern.

 

[whitearrow]

Unless the Japanese put a diff rear end in it as it was 100% made and built in Japan at least that's what the window sticker said. That was a big pull for me for it to be 100% built and made in Japan vs made there and built here. Although my tundra was made in Japan and built in Texas ha!! But given a choice I'd have liked it to be built by the folks that engineered it personally.
Thanks,
Big Ed