[jhautz]

Yes. The ones that come with the RCM Revo Hybrid Diffs are hardend. Just try and tear them up. I was blowing stock revo diffs almost every time I ran the truck untill I got this upgrade. Havent had an ussie since. Only thing I ever did was take them apart to change diff fluids and inspect. They still looked new after months of abuse. Best upgrade ever for the revo IMO.