there is a saying in my family (and I am sure lots of other peoples') that is

don't let them know where your goat is tied up

kind of like

don't let people see where you buttons are sort of thing

i think that your husband knows what buttons to push to get a reaction from you

you loan out the truck
you are strong and tell him you can't possibly get it now because youa re at work
he threatens you and shows anger (maybe your goat is here...you don't like confrontation or you are afraid or intimidated by anger)
you get nervous
he gets to feel powerful

I am suggesting you move that goat
when he makes a totally empty, clearly not in reality sort of threat
(there is no way a sheriff would point a guna t someone and demand a truck be returned...unless they are a felon and armed and dangerous...it isn't grand theft auto...he is trying to intimidate you)
you simply state
i am sorry you are upset about that
i will get the truck back to you asap

when he keeps making demands
simply state
once again, i am sorry you are upset but I really have to go back to work
have a lovely day
goodbye

move yoru goat

he will see that intimidating you doesn't work and will have to try to find a different way to get his way