Fixing Tomica world 7524

Using whatever tools you have you need to get that rod into the new gear. Personally used a hammer and tapped lightly to get the rod further and further into the gear until flush. Then I used the plastic housing hole to get the rod a little bit further through. (Not the best idea I know)

Originally discussed HERE


As for those smaller rods

I used pliers and held the rod against the gear and tapped my hammer on top of the plier
 
I used the same hole from the top housing to hammer through the rod. 
Then use some good ol' lube of your choice on the white plastic gears, put it back together and bam:


For some reason the forum didn't allow me to post everything in one message because of image limits.
Credits to Super & Chrisjo for their inputs regarding the topic.