A fuel injector is operably couplable to a cylinder head, a clamping mechanism being in operable engagement with the fuel injector and the cylinder head for exerting a clamping force tending to hold the fuel injector in engagement with the cylinder head and includes a retainer assembly for retaining the fuel injector in operable coupling with a cylinder head, the retainer acting in cooperation with the clamping mechanism. The retainer assembly has a split dowel, the split dowel being statically engagable with the cylinder head by a clamping action of the clamping mechanism acting on the fuel injector and being engagable with a spring component for imparting a bias to the spring component. The spring component is in operable engagement with the fuel injector for imparting a reactive force to the fuel injector responsive to the bias imparted by the split dowel. And further including a friction coupling, the friction coupling fluidly coupling the split dowel and the fuel injector for generating a frictional force between the split dowel and the fuel injector, the frictional force tending to resist motion of the fuel injector relative to the cylinder head. A retainer assembly as indicated above and a method of resisting relative motion between a fuel injector and a cylinder head are further included.