Roadmaster says use silicone. I tried other lube and it created a mess that trapped dirt really bad and was tough to get off and took a long time. I've had ours bind up and had to turn the wheels of the toad or in gear and let it move a bit. Usually it is the angle of the wheels on the toad. I can't keep the tow bar clean and have to rinse it off good when we unhook and wash it and lube with silicone and let it dry, every time. Roadmaster says to wash it and let dry. Ours is the Sterling and has no raw steel on it to rust. The nylon washers etc are a concern and it probably needs taking apart and new washers and ends etc put on.