it's just a gradual transferrence of the other sense of truck:

1. a. The action or practice of trucking; trading by exchange of commodities; barter. Often in truck (for, †of), by truck for.

b. transf. and fig.

c. with a and pl. (a) A traffic, trade. (b) An act of trading; a bargain or deal.

2. The payment of wages otherwise than in money; the system or practice of such payment, the truck system (see 5); in quots. 1879, 1911, goods supplied in lieu of wages.

3. a. ‘Traffic’, intercourse, communication, dealings. Now usu. in negative contexts: to have no truck with (a person or thing), etc.