Usually 8 washers is about the limit that will fit on that pin. Don't be afraid to add them. Yes, it does increase the effort needed to raise the bars and that is the whole idea. Use the tongue jack to hook up. Here is the process.
1. Couple up the truck and trailer and latch coupler.
2. Raise tongue and truck together quite a bit until you can lift up the WD spring bars quite easily.
3. Hook the spring bar chain in the correct link and draw them up as normal. Should be easy with the tongue and truck raised.
4. Lower tongue and truck back down and raise jack all the way up.
5. Connect rest of your hitch (emergency cord, lights, chains).
6 Remove you chocks.
7. Do a safety check of hitch and walk around trailer to check lights, antenna, steps, forgotten water pressure regulator (I did this once!) and anything else. Make sure rig is ready to roll.
8. Pull out carefully, check brake action, and enjoy your trip.:)
Barney
p.s. You can find a scale at most truck stops and
here.