This is direct from the Equalizer web-site:
"My hitch is noisy, what can I do?
The steel-on-steel friction of the Equal-i-zer hitch will always generate some noise. This is not bad, or a sign that there is something wrong with the hitch or setup. In fact, it usually tells you that your hitch is working just like it's supposed to.
You can do several things that usually reduce most of the hitch noise:
1. Try using a set of Equal-i-zer Sway Bracket Jackets on your L-brackets. These were specially designed to help reduce the noise at this joint, without the mess of using grease.
2. Keep your hitch head clean and the sockets lubricated.
3. Re-adjust the angle of your hitch so that the arms sit more parallel with the trailer frame. For example - when your hitch is hooked up, if your spring arms angle up slightly from the hitch head back along the trailer frame, try adding a spacer washer to the hitch head, and lowering the L-brackets 1 hole. This will give you the same weight distribution, but make the arms more parallel to the frame of the trailer. "
I also use these jackets to help keep the noise down: