Cable end may be worn but shouldn't leak from that. Check the speedo gear housing . Its easy enough to pull it apart and check. Jack the car up enough to get to the tranny ,use jack stands. This will shift trans fluid to the pass side of tranny. Unscrew bolt to speedo housing and work speedo gear out . You will loose about a cup or so of fluid so have a catch pan and rags ready . check speedometer housing for cracks or maybe gear itself. check any seals or O rings for splits check cable end etc.
