cusco diff/ ka trans fluid questions

[mxsx25]

i have a cusco 2way lsd and i was curious if there is any particular fluid i can use to make it a bit quieter... its loud and rough and drives me insane.. also what from experience have you guys had best experience with for trans? i kno these may be stupid questions and simple but i just figured id ask.. thanks guys

[alesserfate]

run motul 90PA in the diff.. a bit pricey but thats as quiet as it'll get.. and last long