5-28 Disassembly/Reassembly Procedures Radio Reassembly - Detailed
5. Insert the top control seal into the volume and channel shaft. Push on the wing of the top 
control seal as shown in Figure 5-38, until it is seated on the base of the switches.
Figure 5-38.  Top control seal reassembly
Ensure the top control seal is seated properly on the shafts.