That one will reverse for you when you change dc polarity/direction sw. if I'm not mistaken
Try to keep voltage under 12-14v on these little ones too. They usually only need 6-9 to run nice anyhow (if you run into acc. cars needing more voltage, you add an oppsed diode chain on the motor so it needs more track volts to begin to move)
Another DC perk: If you change to led headlights, 2 headlamps automatically work directionally if wired in opposing fashion (2 led/ 2 diode/2 resistors).
Plastic/nylon worm gears on axles are old as post war and later horizontal can motor styles that are made in black delrin and do surprisingly well too. (delrin is a self lubricated plastic and needs no lube. I still oil delrin trucks, but it's for rust protection on the axle tip, not to lube)
However the horizontal motor's derin gear retainers, that hold the 1st gear to the armature gear and wheels or other gear, are a little too thin and can crack if you abuse the design with weight and heavy loads and/or intoduce a hard enough phsical shock against the drivetrain. (this was a nice hard chunky steel retainer on old style designs... to bad they didn't just cast those in delrin instead of whittling away the mass for a ΒΌ penny saved.) If your frame has one of the horizontal motors I'd get a retainer or two for the parts box for $2-3 while they exist at shops. (& those old dc motors were still only about $10-$15 last I checked a couple years ago)
