I have had several of the classic white truck sets. They changed over the years and the manuals did not always keep up with the changes.

The manual in my set shows wheels mounted with set screws and cotter keys. Set screws were for rotating axles and cotter keys for non rotating axles. Use of both is redundant.

I have used both in my model. The set screws are loose so the wheel can rotate.

An older manual shows a chassis with cast steering parts, non-rotating axles, and flat springs.

The manual for the model shows a different chassis, formed springs and formed steering mechanism.

The model that I build has the older chassis. The manual has models with both types of chassis.

The older model. Note that the wheels are held on by an even older arrangement, screws into the axle ends. The pictures in the manuals did not always keep up.

The manual picture for the model I built.

The model. The newer manual does not show how to build the tail gate hinge, the older manual does.