Ball diff grease from schum ( the grease in the plastic bag )is great .So i have ordeerd some in small can ,but it's not the same quality . i have try it and impossible to have a diff that doesn't slip grrrr .
So i go back to associated who is top quality.( tamiya is also very good).
One tips before rebuild your diff is to lightly go with "sand-paper" on the diff ring .
(from left to right and up to down ,not concentric)
this helped the diff ball to roll instead of slice .So you can use your diff longer between rebuild .
"Difference " is greater than expected.
i now go back to build my sx3