Been there. Done that. Poorest design ever. Had mine make problems in just a few months. Then was told by APR that I installed it wrong. That the spacer was pressed on, and that the spring shouldn't have deformed from the weight of the spacer.
Needless to say, I love my McLeod adjustable TOB. It also requires a spacer, but that goes BEHIND the TOB. And it uses flex lines, with the adapter that I posted on the 1st page. Works like a charm.