I need someone's advice with these spring loaded rachet type tensioners on the M102 engines please. Even with the rachet engaged into the body the plunger itself can go backwards into the body when pressure is applied but only by 4mm or so then it stops. By means I am able rock the plunger back and forth while the rachet system is engaged into the tensioner body. Is this normal? Are they design to do this? I was thinking they shouldn't be able to go backwards at all? Anyone's advice will be much appreciated. Thanks