The cast nuts used in this unit are an unknown size. The stock 19mm doesn't fit and the calipers measure 19.6mm. I hope socket 25/32 works, otherwise I'll send it back. Come on NewYall, can't you even get this simple spec right? Update: February 25, 2112, Item 25/32 socket stripped cast nut. So there is absolutely no way to loosen the tension with standard tools. install it