As often as possible eyeball what is or is not going on underneath. It is one of those out of sight, out of mind things.
As suggested above, upgrade the shackles & hang on to the old ones just in case. Upgrade to wet bolts & carry a couple spare. We hit one heckuva dip south of Calgary, AB once. Unbeknown to us it sheared a wetbolt. Lucky for us the pieces stayed in place & we did not figure out what had happened till many miles later.
We had spares & the tools needed to do the job. DW & I changed it out in a CG on our own.
As long as you are thinking upgrades, think about the spring packs. Seen one fail in AK. Lucky driver was right next to a CG when it happened. New trailer. Undersprung & overloaded. Inexpensive upgrade. I went from a 6 to a 7 pack. Still managed to break a couple of leaves in those in Newfoundland. The roads are that bad.
Trailer running gear too often is only minimum spec.
