Ok, I don't know what its called but, the piece used to keep the stretcher locked in place wont lock. I search a lot and could not find anything. What happens is when load the stretcher the notch on the stretcher hits the button on the rail and pushes it in and then I have to pull on the handle for it to lock. I have smothered it in WD40 and check the notch on the stretcher which is out as far as will go. Don't know what else to do. Any help will be appreciated. Sorry for my typing it sucks.