I found my Equal-I-zer manual and found this:
Noise is a normal occurance when towing a trailer and using any weight
distribution or sway control hitch.
In some cases the friction on the L-brackets or sockets also generates
noise. This most commonly occurs during slow, tight turns where the tow
vehicle and trailer are in a twist. This noise is normal and should be expected.
It is an indication that there is friction on the L-bracket and sockets.
Most of the noise will usually subside after a few uses as the hitch breaks in.
Trailer and tow vehicle loading may also influence hitch noise.
Lubricating the socket joint may help reduce this noise, and is part of
the required regular maintenance routine. Lubricating the L-bracket joint is
optional. A better solution is a set of official Equal-i-zer brand Sway Bracket
Jackets™. They quiet the ride without the mess of using a lubricant.
I found them for around $35 for a pair on Amazon (didn't have free shipping) so I'm going to buy them. Product Description:
Equal-i-zer Sway Bracket Jacket
- The Sway Bracket Jacket was designed to quiet the ride and reduce wear on the L-brackets of your Equal-i-zerŪ hitch. Injection molded from high density polyethelene plastic (HDPE). Each package contains two (2) Sway Bracket Jacket, one for each L-bracket.