Yamaha DTXpress/DTXplorer/DTXtreme

When I acquired by DTXpress kit, I noticed that the RIDE pad when 
hit,  mysteriously swayed left or right. This did not happen when the 
crash pad was hit. AHHH!!!
The crash pad, I found out,  with extra scrutiny, has a locking nut. 
Off 
this locking nut is a rod that sticks out,  that neatly aligns itself 
in the "slit" that is located in the back of the crash pad...Clever 
idea!!
However, my problem...I am missing this piece on my ride pad. A very 
minute part, but its presence is important..
Apart from ordering this part from Yamaha (cost = $45.00...blew my 
mind!!), where else could I acquire this piece, or what 
modifications, if any,  can I conjure to prevent the pad from swaying 
like a kite.