the door jam will tell you. . .
look for somthing saying "GVW" or "GVWR" take the truck's weight and subtract it from that number that will give you the pay load. . . the V-40 i would say 5,000lb and the V-60 12,500lb. . .
my K-3000 GVWR 12,500 truck with the dump bed was 7,000lb so it's payload was 5,500lb. . . truck now might only be 6,000lb so now pay load maybe as high as 6,500LB. . .
GVWR= truck payload fuel people maximium total weight. . .
example 1: my K-3000 GVWR:12,500LB truck empty weight 6,250lb
cargo can't weigh more than 6,250lb. . .
example 2: my B61T GVWR: 120,000lb's truck empty weight is 17,500lbs so trailor+cargo can't weigh more than 102,500lb. . .
example 3: my M123A1C GVWR: 300tons (600,000LB) truck empty weight 21 tons (42,000LB) so trailor+cargo can't weigh more than 279tons(558,000LB). . .<<< Big truck more like HUGH! truck. . .
make the truck ligher payload goes up. . . make truck heavyer payload goes down. . .
hope that help's I might have just confused you more. . .
Mike