I wanted to try something different and after reading a few posts here about using the Stampede as a crawler I thought I'd do my own take on it. Pretty much everyone agrees that normally this truck can't be geared low enough so I did a bit of research on crawlers and found some people using an airplane gear reduction unit on their trucks for a larger reduction ratio.
The one I read about was the GD-600 by ElectriFly
For $15 bucks I thought I'd give it a try. The only modification I had to do is enlarge the center hole on the motor mounting plate and clearance the GD-600 to clear the mesh adjusting screw. Since the output of this drive is 5mm, you will also need to get a 5mm pinion if you don't have one already.
I also got the optional 3.8:1 gear to lower the standard 2.5:1 the unit comes with.
With a 13 tooth pinion and a 56 tooth spur this lowers the overall gear ratio to 46.5:1 versus a 12.3:1 without the reduction unit. Final speed is just a bit faster than I can walk.
I have only ran it about an hour so far but I'm really pleased how it turned out and using a no-name brushed motor I got from a surplus store it has plenty of power and runs cool over all types of terrain.