have read a couple threads on my car-specific-forum about which diff fluid i should run in my car.
apparently 1.5 quarts of a conventional 75w-90 or 80w-90 + a bottle of Ford Friction Modifier has been good for many people. Motul 90pa is another good option.
my question is...would the mystik JT-7 be a suitable replacement? what does the friction modifier actually do? modify what? should i use the FFM with the mystik fill?
this is going to be used on my tomei clutch type (i think ) LSD
edit - just found Shell 80W-90 Spirax Heavy Duty Gear Oil for $2.72 a quart....might go with this instead. is this formulated for an lsd differential?
apparently 1.5 quarts of a conventional 75w-90 or 80w-90 + a bottle of Ford Friction Modifier has been good for many people. Motul 90pa is another good option.
my question is...would the mystik JT-7 be a suitable replacement? what does the friction modifier actually do? modify what? should i use the FFM with the mystik fill?
this is going to be used on my tomei clutch type (i think ) LSD
edit - just found Shell 80W-90 Spirax Heavy Duty Gear Oil for $2.72 a quart....might go with this instead. is this formulated for an lsd differential?
Last edited by a moderator: