grease leaf springs?

Yeah my shackles pop too when making a turn at speeds of 2-3 mph. My old trailer did the same thing. I've never had any problems and the springs/shackles never broke.

I'm not saying something could go wrong in the future. Maybe a touch of grease on the shackles where there is some bare metal showing from rubbing, might help. The popping sound is obviously some binding going on.