rear axle movement desc410r

[asc6000]

My first Durango, why does this have so much movement?
Iv'e been rc'ing for a long long time and am a very good builder so this is killing me. Checked each part seperately and each interface (axle in bearings/bearings in hub/hub on hinge pin etc) and it adds up to a lot of slop. Shimmed reshimmed checked rechecked... help me out Durango veterans
http://www.youtube.com/watch?v=-ZkFOraTOT0
As long as I have you, I was told my choice of electrics RSpro and 540 motor will not be not be up to the stress of this truck, should I use 1/8th scale stuff?...

thank you