the truck was designed for PLA. Nylon will shrink a lot more. PET-G also will shrink slightly more then PLA. i recommend just a few parts printed from nylon. the small 4 bevel gears in the center and axle diff(12 total), and the 4 wheel axles(inserted into the rims). PET-G would work better for the suspension arms for some collision flexability the rest just PLA with good fusion on the layers. the 3mm rods just slide in no glue.
I like to glue the large bevel gears to the axle shafts so the shafts do not come out of the gear ends.
i recommend changing the dogbone style shafts to CVD style. there are a few remixes on changing the drive shafts.
depending on your gear mesh you might need my 29T lower axle diff replacement gears.
besides cube tests there are also tolerance tests for shapes and round holes to weed out mechanical problems with your printer and slicer settings