Thanks the reply Andy.
Check I have the plate inside the torque box area not behind the hanger.
For some reason I was thinking there was more thread to get into the factory encapsulated washer and nut. But that was late last night after I had finished hanging everything.
Now that I have another look at it there is full engagement of the threads and a little more sticking out of the nut.
I think what got me more messed up is the local spring shop set me up with U bolts for the axle that are 19MM. The 3/4 Impact socket was just a tad too small for them.
Sorry about that...