So I have been upgrading my Granite Mega, I stripped the spur gear. I purchased a new spur gear assembly for the BLX version but I cannot get the motor unit to click into the diff. Is the output on the motor unit a match for the original stock differential gear or is it different. I see that the mega is black plastic and the BLX looks to be shiny metal. I keep upgrading after upgrade and wish I would have just gotten a BLX in the first place. Any help with this would be appreciated.