Abstract: A shock-absorber subassembly for a subsurface drilling assembly is disclosed. The shock-absorber subassembly comprises a mandrel, a body assembly, and at least one torsional spring assembly. The mandrel has a bore extending therethrough and has one end connectable to a portion of the subsurface drilling assembly. The body assembly has a bore extending therethrough and one end connectable to another portion of the subsurface drilling assembly. The body assembly is coupled to the mandrel to establish fluid communication between the bore of the mandrel and the bore of the body assembly and to permit planar rotational movement of the mandrel relative to the body assembly. The at least one torsional spring assembly engages the mandrel and the body assembly to absorb torsional shocks and vibrations between the mandrel and the body assembly and to limit the degree of planar rotation between the mandrel and the body assembly.