Locking the revo in 2nd gear to use motor braking/reverse

[offroader]

I believe BrianG said the input and output shafts should modded.

His quote
Those pins replace the ones currently in the tranny. There are two places where these go; on the input gears (blue ones in the pic in the first post), and on the output gear that is on the output shaft. These pins secure the gear to the shaft.