Originally Posted by
antlockyer
As I mentioned before I put 2 extra shims in the diff and tightened it fairly tight. This is what it sounds like now just under power.
https://youtu.be/b8qHBdhH-ig
Is that normal? Sounds awful to me

Doesn't sound
that bad, for a mini. I'd strongly suggest replacing the pinion with an aftermarket one, or a hardened Tamiya version. The stock ones go all shark toothed in short order.