Regarding your clutch Racegypt. One thing you might want to try is to remove the clutch and shave out a little plastic from the 3 holes on the clutch. just enough to smoothen it out though, after make sure that the clutch is moving up and down smoothly on the post. Your clutch may not be engaging properly because there is some sort of binding between the three pins and the clutch. thats what i did on my GPX4.
I hope this helps
Also don't forget to wipe off the excess grease inside of the two speed or else your car will not shift properly. The grease comes from the bearing.