Mixing Brands of Differential Fluid

Hello everyone, I had a quick question that I can't seem to find an answer to.

Is there any issue with mixing brands of differential gear fluid?

I don't mean draining the differential, and then switching to another brand. What I mean is for example: you put 2 quarts of OEM differential fluid in, and then 1 quart of Red Line 75w-85 GL-5.

Would this cause any problems?

I ask because I just put in 3 quarts of the Toyota OEM 75w-85 GL-5 into the rear differential, but it didn't quite start dripping out of the fill hole. I'm not sure if I'll be able to run out to the dealer tomorrow to pick up another liter of it, so I wanted to know if grabbing Red Line from an auto store as a backup just to top it off would be ok.

Thanks in advance

 

You'll be fine.

 

Thanks, while I'm already asking on the topic, I'm assuming I should be ok to drive a bit with just 3 quarts of fluid in the rear diff?

I did feel the fluid when I stuck my pinky in there, but it just wasn't dripping out of the fill hole with a steady flow like all the directions everywhere state. I should have just bought the extra can, but I could have swore every place stated under 3 quarts go in.

 

I definitely parked the car on as level of a surface as I could, however there was an ever so slight decline. I did park it in the direction that made the fill hole face "up hill" specifically because of what you mentioned (I rather slightly overfill than underfill).

Regardless, I'll have it topped off as soon as possible. I was just more concerned with if I'd be able to make a 70 mile round trip like this if it came to it.

 

Thanks again!

 

This is where, after running low on fluids or breaking a tool, Amazon Prime comes into play. While fluids are harder to get shipped, Amazon has no problem with it and there is a small premium for that. Walmart also does some locally based shipping that might get a fluid to you.

Within the last two or three weeks, my Performance Tool hand pump (for transmission fluid), a couple of pieces from my 30-year-old vanadium socket set, my Craftsman socket driver and my oil filter removal tool all broke on. Lost on a couple of different cars.