Upper arm replacement

Dishwasher Repair
1

I am trying to install part #wpl675808. Even using the thicker ring, the arem will not clear the bottom rack on the right hand side. Any suggestions?

2

Is there enough pressure in the system when the pump is running?

Is there enough water in the dishwasher?

Do the both arms spin when the pump is running?

Here are the break down diagrams for the Kitchen Aid dishwasher Model KUDR24SEBL2

Gene.