Chock one trailer wheel. Jack up the trailer tongue with the tongue jack or a floor jack. Support the tongue with lumber or blocks.
Attach the safety chain to the trailer behind the tongue with a high-strength bolt, nut and washers. Use bolts with large heads or washers to prevent the safety chain from pulling through the bolt under load. Tighten the bolt and nut with a socket wrench and crescent wrenches.
Adjust the safety chain length to prevent it from dragging on the ground. The chain length should also prevent the trailer from dragging on the ground if it disconnects from the tow vehicle.
Connect the trailer to the tow vehicle. Back up the trailer from side to side and confirm the chain length will permit a 90-degree turn in either direction. This should be the maximum chain length allowed for the safety chains.
Inspect all connections and chain-mounting hardware. Connect the chains every time you tow the trailer.
