Pumps and plunger assemblies are provided. An exemplary pump can have or contain a cylinder mounted in a pump housing, a plunger assembly including a crosshead, a plunger, a stationary bushing having substantial portions fixedly mounted within a laterally extending bore of the crosshead, and a non-stationary pivotally rotating wrist pin mounted within the bushing. The pump can also include a power end seal assembly including a seal housing extending at least partially through an aperture in the sealed fluid end-facing side of the power end of the pump, a power end seal disposed therein in sealing contact with the power end section of the plunger and a splashguard assembly.