Problem putting gas in truck

[PRattenbury]

Well, before I went to the tranny shop with my truck I had to stop and get some gas. My truck is a 1980 short bed fleet side and the single tank is on the right side of the truck. Anyway, I started putting gas in the truck, and the nozzle clicked off. I kept trying to put gas in, and the nozzle kept clicking off. A few times, the gas just backed up in the filler hose and a little even belched out. The tank was not full, but that's what it was acting like. I recall when the truck was in my garage when I was getting ready to start the truck up and break in the cam I went to put 5 gallons of gas in the tank from a can and it would only take gas very slowly then. So I'm wondering if there is a common problem with these filler hoses that I should be aware of, and maybe a solution to the problem. Maybe a venting problem? My ears are open!