Problems with Demco Autoslider not hitching

Thanks for the replies! There are three height adjustments on the demco. I've adjusted it to the medium setting and now the locking bar is moving further over than before and i can easily insert the cotter pin into the handle to lock the bar into place. However, it is still not where it is suppose to be. I will apply some grease today and see if that helps. Decmo customer support has been great by the way.