GPM motor cradle not meshing right?

[Bananabrain]

Ok, well I ordered a GPM motor cradle for the Evo, installed it and put in the 9 tooth gearing and that meshes properly. But were the main gear mesh's with the Diff, it is not meshing right it is skipping teeth and I can't move the car when it is sitting on the ground.

Any ideas on how too fix it? Or do I need to order a GPM rear gearbox cover?

Also the screws are all in nice and snug and it runs while being held in the air, but when its on the ground it grinds.