Knocking, Rattling, Squealing noises plagued my bafang- planetary gear hub motor on my 2019 Volt Yukon 750 after an accumulated 13,000 miles. Of the number of possible issues that could go wrong (motor) internally, I've identified an issue to be a likely a common problem showing these symptoms (knocking, Rattling, Squealing) and a temp Fix (way to prolong motors life) Savings: $Hundreds