Towing my sled with a snowmobile.

[mjlevie]

Replace the bolts on the sled to these




And then attach the bars to the sled with either of these







Those will not come undone when traveling. If so carry a small wrench for that twist nut though. It can get tight when it's cold or corroded a little

Agree with this.  I always had mine come off the hooks. The eye bolts  have been great. I prefer the twist nuts as I've had the snap type bend and come off.  Make sure you get robust snaps if you go that route.