I have a 450g that I just bought and it didnt have 1st gear called the guy and he said it was a linkage adjustment, so I pull the cover off under the shifter and there is a brand new shift rod there but both of the jam nuts are backed off. So I put it in gear where 1st should be and start turning the rod and 1st catches I can adjust the rod where I have all 4 gears but the dozer wont crank. I can adjust the rod where it will crank but only have 2 3 4 gear im sure there a proper adjustment. Any advice would be great. Thanks