It could be one of three problems.

1. The oneway is slipping because it's saturated with oil. You can can fix this by pulling the owb out and cleaning it with nitrocleaner or any degreaser.

2. There is a spring loaded pin the comes out of the connecting rod that grabs the backplate,this pin could of fell out. You can fix this by pulling the back plate off an reinstalling. When you put the pin back in place, do it gently or the pin will fly out.

3. your owb is blown.