Okay. 1) Go into the .truck file 2) scroll down to the flexbodies section. 3) find the lines like this
131,73,135, 0.5, 0, 0, 0, 180, 0, Uktire.mesh
forset 131, 73, 135-158
130,72,159, 0.5, 0, 0, 0, 0, 0, Uktire.mesh
forset 130, 72, 159-182
;RR
47,132,183, 0.5, 0, 0, 0, 180, 0, Uktire.mesh
forset 47, 132, 183-206
;RL
48,133,207, 0.5, 0, 0, 0, 0, 0, Uktire.mesh
forset 48, 133, 207-230
4) make yours look like the ones that are highlighted. They are normally 0 but to rotate them put in 180.