RL02 latch cable

Does anyone have some experience with the best way to "lubricate?" the cable in the top cover of an RL02 drive? I can't tell for sure if the cable is wire or plastic or plasticoated wire or fiber..... The issue is probably typical... when you release the hand operated slide the clasp on the top cover at the front doesn't slide back all the way to latch the top closed. I am sure that it is not the spring in the front latch. Moving that by hand, there is plenty of spring tension left. The problem is definitely that the cable between the front latch and the hand operated slide isn't "sliding" in the channel. What good way have people found to address this. If it's fiber I was thinking of sliding the cable through wax once or twice. Is there a better way? Graphite would seem a bad idea.... Jay