A motion transmitting remote control assembly (10) comprising a conduit (12) having an inner surface slidably supporting a motion transmitting core element (16) and a coating of lubricant (28) on the core element (16) for reducing friction between the core element (16) and the inner surface of the conduit (12). The assembly (10) is characterized by an additive material (30) of phosphorous mixed with the lubricant (28) for visually determining the presence of lubricant (28) with ultra violet light (32) . The invention also includes a method of checking for the presence of a lubricant (28) on the core element (16) comprising the steps of mixing a lubricant (28) with a phosphorous material (30) , applying the mixture to the core element (16) and subjecting the core element (16) to ultra violet light conditions (32) to visually inspect for the coverage of lubricant (28) over the core element (16) .