Cox car (Riviera and others) fan/flywheel/drive gear

I got a replacement spur gear for my Gurney Eagle from a US company called goBILDA. I think you can order the same part straight from China. The number "1" on the original gear appears to have been misleading, a 40 tooth gear with 1 metric pitch would be bigger. The one I found is 0.8 pitch 40 tooth with about the same dimensions. Even the axle hole is hexagonal, Cox style.



It seems to mesh well with the motor pinion gear. However, there are differences that have to be modified:
-The axle hole is too large, metal tape or something is needed for a tighter fit.
-The tooth face width is a bit too much and may have to be filed down.
-Most importantly the stem is too thick, touches the motor flywheel end and prevents the teeth from meshing. The stem has to be thinned down, hopefully with the set screws still useful.

Original gear and new gear
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