My trailer had been squeaking for a little while on bumps and such for a while. Last tournament I fished I noticed it clunked when my Co took tight turns to swing around and line up on the ramp. Finally got the chance to crawl up under it to spray everything with some lube and check it out.
I found a total of 1 bolt that was actually tight in the whole leaf spring assembly. I know suspension bolts aren't sinched down, but these things were LOOSE. The rear leaf spring bolt on one side was so loose there was a half inch gap between the leaf eye and the hanger tab and the nut nearly off the bolt. I would imagine that clunk I heard was where the leaf would shift on turns to the other side.
I sprayed and torqued every bolt on it so hopefully my squeaks and clunks are done.
Take the time to check your suspension bolts on your trailers guys