The more I look at it, the more it looks like part# 5351 has either changed, or this part is different between nitro & electric models. The pic in the traxxas instructions show a difference in the number of fins, yet they have the same part #... If you look at Ralf's pic of his old slipperential as well, it looks like his had only 5 fins, instead of 10 like mine. Maybe I need to order a different kit...