Chucking?

A trucker once told me to grease the hitch plate to stop chucking. It didn't make sense because I think of grease as a lubricant so in my mind it should make the chucking worse. It doesn't it stopped the chucking with my old RBW hitch. The trucker explained it this way; the grease due to viscosity and pressure helps lock the hitch plates together and provides shock absorbing by reducing slippage of the plates/hitch pin.

My current B&W Companion hitch hasn't had any chucking issues in the 10 years I've been using it. It appears B&W has designed the hitch to eliminate chucking.