There is nothing worse than when in low range going down a slope with the auto in second gear and having to slow up just a bit for a obstacle or corner and to have the auto change back to first throwing you forward in the seat. You then have to speed back up a bit and shift the gear lever back to third and then back to 1-2 position until the next time you slow up a bit. It's fine if the hill is steep enough for using first all the way as it will stay in first until the red line but you don't always want to be going that slow! Now this modification will allow you to leave it locked in second gear using a switch to hold it there.
See my how to section for the details!
See my how to section for the details!