The bushings used on the brake proportioning valve pivot.
There are 2 used.
Part # 4604300023
Part # 0024311312
Part # 4604300192
Part # 4604270321ET
Part # 4604270121
Part # 4604270221
Part # 4634300292
Part # 4604300110
Part # 9009850
Diagram # 08-15-15