Below are some very useful information about how to shim the diff and transmission of your HPI Savage monster truck as well as the parts to use do the shimming.
Kyosho 8x10mm diff shim kit
Diff shimming 101
Shims for Savage Diff and Transmission
Savage Diff Oil Weight
Interior diff shim?
If you have wondered how different diff oil thickness or thinness effects your rear, center, and front diffs then the below chart should help you out.
Kyosho 8x10mm diff shim kit
Diff shimming 101
Shims for Savage Diff and Transmission
Savage Diff Oil Weight
Interior diff shim?
Differential weight explained
If you have wondered how different diff oil thickness or thinness effects your rear, center, and front diffs then the below chart should help you out.