hey everyone. i know for the rear differential fluid it is 75w90. my question is .. i have leftover redline mt-85 tranny oil from before and i have a bit of amsoil 75w80 tranny oil left. would it be safe for me to mix both together and use it on the rear differential? just wondering so i would know if i needa order another qt if i cant do so. the rear diff capacity is about 0.58 qt right? or about 1 qt? thanks everyone.

 

err i mean 75w-90 for leftover amsoil. my mistake

 

Me personally, I only use what is supposed to go in there. Oils today are much more that just a # (ie 75w90). There might be some additives in that tranny fluid that aren't supposed go in the diff. I'm sure you're asking because you want your car back up and running. For next time you drain the fluid, make sure you have enough around to fill it back up.