As much as I'd like not to upgrade my mini z, there are a few things that must be done. Replacing the bearings is one of them. I bought the PN racing bearings that can be found here. It made my car run smoother and much quieter. There are 7 bearings in this pack and the pictures above will show you where you need to install these. 2 in each of the front wheels, 1 in the rear wheel (spur gear side) and 2 on the motor mount where the differential shaft goes through.
