Ok so I've searched on here for a while and I've found the answer to my question but its not a straight forward answer. I know this topic has been covered a lot, I just want to make sure I'm getting the right stuff. I'm replacing my old broken diff with an MFactory diff and I need to know which MTF to run. I know there's a lot of fluids out there but some require an additive when running a limited slip or they require a GL-4 or GL-5 fluid. Can I use something like the mobile 1 syn. 75w90 gear oil?