On the right is the base with rebound adjuster knob. The shaft is on the top. Notice the hole just bellow the shoulder. Inside the shaft is a rod to move the needle, the rebound needle and the check valve. Oil passes the needle by flowing into the shaft through the hole below the shoulder, past the needle and out the check valve. The piston with compression and rebound stacks rest on the shoulder.
What’s In A Shock Shaft?
