On my friends G, (2000 G500) the shifter will not allow him to go down lower than drive. It will just physically not allow it. He says that since he owned it that the shift into lower gears was rough, but doable. Now it wont go at all. I have completely removed the box from the truck and with it sitting on the bench the same condition exists, so it's not the transmission or it's linkage. Any ideas. I hesitate to take the unit apart, but I will if I have to. Or should I not? Help us out. It's GWhizz's G were talking about.